In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.

Let me give you an example: Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin? Passage 1: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lô during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Passage 2: John Ford (1894–1973) was an American film director whose career spanned from 1913 to 1971. During this time he directed more than 140 films. Born in Maine, Ford entered the filmmaking industry shortly after graduating from high school with the help of his older brother, Francis Ford, who had established himself as a leading man and director for Universal Studios. After working as an actor, assistant director, stuntman, and prop man – often for his brother – Universal gave Ford the opportunity to direct in 1917. Initially working in short films, he quickly moved into features, largely with Harry Carey as his star. In 1920 Ford left Universal and began working for the Fox Film Corporation. During the next ten years he directed more than 30 films, including the westerns The Iron Horse (1924) and 3 Bad Men (1926), both starring George O'Brien, the war drama Four Sons and the Irish romantic drama Hangman's House (both 1928 and both starring Victor McLaglen). In the same year of these last two films, Ford directed his first all-talking film, the short Napoleon's Barber. The following year he directed his first all-talking feature, The Black Watch.
. Passage 3: Since the late 1970s, the central part of NYU is its Washington Square campus in the heart of Greenwich Village. Despite being public property, and expanding the Fifth Avenue axis into Washington Square Park, the Washington Square Arch is the unofficial symbol of NYU. Until 2008, NYU's commencement ceremony was held in Washington Square Park. However, due to space constraints, ceremonies are now held at the Yankee Stadium. Important facilities at Washington Square are the Elmer Holmes Bobst Library, designed by Philip Johnson and Richard Foster, who also designed several other structures, such as Tisch Hall, Meyer Hall, and the Hagop Kevorkian Center. When designing these buildings Johnson and Foster also set up a master plan for a complete redesign of the NYU Washington Square campus. However, it was never implemented. Other historic buildings include the Silver Center (formerly known as "Main building"); the Brown Building of Science; Judson Hall, which houses the King Juan Carlos I of Spain Center; Vanderbilt Hall, the historic townhouse row on Washington Square North; The Grey Art Gallery at 100 Washington Square East, housing the New York University art collection and featuring museum quality exhibitions; the Kaufman Management Center; and the Torch Club – the NYU dining and club facility for alumni, faculty, and administrators. Just a block south of Washington Square is NYU's Washington Square Village, housing graduate students and junior and senior faculty residences in the Silver Towers, designed by I. M. Pei, where an enlargement of Picasso's sculpture Bust of Sylvette (1934) is displayed.
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The answer to this example can be: 1
Here is why: The question refers to the 704th unit and task about war which is decribed by Passage 1.

OK. solve this:
Question: On what date did the Open 13 begin? Passage 1:During World War II it was one of the few cartridges used by both the Axis and Allied powers, a distinction it shared with the 9×19mm Parabellum pistol round. Apart from being the standard rifle cartridge of the German and Polish armed forces, it was also used by the armed forces of Great Britain in the Besa machine gun, which was mounted in some of their tanks and other armoured vehicles, as well as being extensively used by the Chinese, especially early in the war. After World War II it was used by the early Bundeswehr of West Germany. Later, when Egypt decided to manufacture the Hakim rifle, a licensed copy of the Swedish Ag m/42, they redesigned the breech to accept the 7.92×57mm Mauser cartridge rather than use the original 6.5×55mm Ag m/42 cartridge. Its military use continues today (2012) in the former Yugoslavia in the Zastava M76 sniper rifle and the license-built copy of the MG 42, the M53 Šarac machine gun.
 Passage 2:In February 2008 Speranza was appointed by PD's secretary Walter Veltroni to the national committee of Young Democrats, with the task of creating the new youth organization of the Democratic Party. On 9 November 2009 he was elected regional secretary of the PD for Basilicata. After supporting Pier Luigi Bersani in the 2012 primary election for the choice of the centre-left candidate for Prime Minister in the 2013 general election, he was selected by Bersani to coordinate his 2013 electoral campaign. The centre-left alliance Italy Common Good obtained a clear majority of seats in the Chamber of Deputies, thanks to a majority bonus that has effectively trebled the number of seats assigned to the winning force, while in the popular vote it narrowly defeated the centre-right alliance of former Prime Minister Silvio Berlusconi. Close behind, the new anti-establishment Five Star Movement of comedian Beppe Grillo became the third force, clearly ahead of the centrist coalition of outgoing Prime Minister Mario Monti. In the Senate, no political group or party won an outright majority, resulting in a hung parliament. Speranza was elected to the Chamber of Deputies in Basilicata's electoral constituency.
 Passage 3:Juan Martín del Potro reached the quarter-finals of the first slam of the year in the Australian Open losing to Roger Federer. He then reached his first final of the year at the ABN AMRO World Tennis Tournament losing to Federer once again. However, he bounced back by winning his first title of the year at the Open 13 defeating Michaël Llodra in the final. At the Estoril Open, successfully defended his title by defeating Richard Gasquet . At the French Open he reached the quarter-finals but fell to Federer for the fifth time in the year despite leading two sets to love he lost. At Wimbledon he was handily defeated by David Ferrer in the fourth round. He bounced back at the Olympics winning the Bronze Medal match over Novak Djokovic after losing to Federer in the semifinals. At the US Open he reached his third slam quarter-finals of the year but lost once again this time to Djokovic. He won his third title of the year at the Erste Bank Open defeating qualifier Grega Žemlja in the final. At the Swiss Indoors Basel, Del Potro got his fourth championship of the year after beating Roger Federer. This is the third time del Potro has qualified for the event.

Answer:
3