Detailed Instructions: 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.
Problem:Question: What was the population of Pine Bluff the year Gordon led his regiment at the Battle of Marks' Mills? Passage 1:In March and April 1864, Shelby's men harassed and skirmished with the Union Army force under the command of Major General Frederick Steele during his Camden Expedition, part of the Red River Campaign. Gordon led more than one charge against the Union forces during Steele's march from Little Rock to Camden, Arkansas. On April 25, 1864, Gordon led his regiment at the Battle of Marks' Mills where they captured two Union artillery pieces from the detachment of Union Lieutenant Colonel Francis M. Drake when Shelby's force attacked the Union left wing of the detachment which had been sent from Camden toward Pine Bluff, Arkansas to obtained supplies for Steele's force which was increasingly besieged by gathering Confederate forces at Camden. The Confederates outnumbered the Union force at Marks' Mills by more than 2 to 1 and overwhelmed it, taking about 1,300 prisoners and about 240 wagons. The overall commander of the Confederate cavalry force at Marks' Mills, Brigadier General James Fagan, led the Confederates, including Shelby's command, toward Pine Bluff in an effort to capture the Union supply depot. The Confederates did not make it to Pine Bluff due to flooding. They also did not return fast enough to cut off Steele's return march to Little Rock or to participate in the Battle of Jenkins' Ferry, the one big engagement during the retreat before the Union troops escaped across the swollen Saline River.
 Passage 2:The existence of an Abydos Dynasty was first proposed by Detlef Franke and later elaborated on by Kim Ryholt in 1997. Ryholt observes that two attested kings of this period, Wepwawetemsaf (Wepwawet is his protection) and Pantjeny (He of Thinis), bore names in connection with Abydos: Wepwawet being an important Abydene god and Thinis being a prominent city, located a few miles north of Abydos. Additionally, Wepwawetemsaf, Pantjeny and Snaaib, another king of the period, are each known from single stelae discovered in Abydos, which could be a sign that this was their seat of power. Finally, Ryholt argues that the existence of an Abydos Dynasty would explain 16 entries of the Turin canon at the end of the 16th Dynasty. The Abydos Dynasty may have come into existence in the time lapse between the fall of the 13th Dynasty with the conquest of Memphis by the Hyksos and the southward progression of the Hyksos to Thebes.
 Passage 3:The Derg overthrew the Ethiopian Empire and Emperor Haile Selassie in a coup d'état on 12 September 1974, establishing Ethiopia as a Marxist-Leninist communist state with itself as a military junta and provisional government. Various left-wing, ethnic, and anti-communist opposition groups supported by the United States began armed resistance to the Soviet-backed Derg, in addition to the Eritrean separatists already fighting in the Eritrean War of Independence. The Derg used military campaigns and the Qey Shibir (Ethiopian Red Terror) to repress the rebels. By the mid-1980s, various issues such as the 1983–1985 famine, economic decline and other after-effects of Derg policies ravaged Ethiopia, increasing popular support for the rebels. The Derg dissolved itself in 1987, establishing the People's Democratic Republic of Ethiopia (PDRE) under the Workers' Party of Ethiopia (WEP) in an attempt to maintain its rule. The Soviet Union ended its support for the PDRE in the late-1980s and the government was overwhelmed by the increasingly victorious rebel groups. In May 1991, the PDRE was defeated in Eritrea and President Mengistu Haile Mariam fled the country. The Ethiopian Civil War ended on 4 June 1991 when the Ethiopian People's Revolutionary Democratic Front (EPRDF), a coalition of left-wing ethnic rebel groups, entered the capital Addis Ababa and overthrew the WEP. The PDRE was dissolved and replaced with the Tigray People's Liberation Front-led Transitional Government of Ethiopia.

Solution:
1