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.

Question: What car did Sommer drive in the Vanderbilt Cup? Passage 1:A primary cause of wound dehiscence is sub-acute infection, resulting from inadequate or imperfect aseptic technique. Coated suture, such as Vicryl, generally breaks down at a rate predicted to correspond with tissue healing, but is hastened in the presence of bacteria. In the absence of other known metabolic factors which inhibit healing and may have contributed to suture dehiscence, sub-acute infection should be suspected and the protocol of obtaining wound cultures followed by treatment with the appropriate antibiotics should be undertaken. Dehiscence can also be caused by inadequate undermining (cutting the skin away from the underlying tissues) of the wound during surgery, excessive tension on the wound edges caused by lifting or straining, or the wound being located on a highly mobile or high tension area such as the back, shoulders or legs. Individuals with Ehlers–Danlos syndrome also commonly experience wound dehiscence. Risk factors can include any of the above as well as obesity, smoking, previous scarring, surgical error, cancer, chronic use of corticosteroids and increased abdominal pressure. A very common cause is also use and especially overuse of nicotine in any form. Smoking should therefore be stopped a certain time before any surgery.
 Passage 2:Sommer was born in Mouzon, in the Ardennes département of France, into a wealthy Sedan carpet-making family. His father, Roger Sommer, broke the Wright Brothers' record for the longest flight in 1909. It was not until 1931 that Raymond started to display daredevil tendencies of his own, entering motor races in a privateer Chrysler Imperial. The following year, he won the 24 Hours of Le Mans race, despite having to drive over 20 hours solo after his teammate, Luigi Chinetti, retired ill. During the 1930s, Sommer was to dominate the French endurance classic, winning again in 1933 driving an Alfa Romeo alongside Tazio Nuvolari. He also led every race until 1938, only to suffer a mechanical failure, once when 12 laps in the lead. Sommer traveled to Long Island, New York, to compete in the 1936 Vanderbilt Cup where he finished fourth behind the winner, Nuvolari.
 Passage 3:Khánh had long been regarded as an ambitious and unscrupulous officer. Following the partition of Vietnam, Khánh, a French-trained officer who served in the French-backed Vietnamese National Army during the First Indochina War, had rallied to support Ngô Đình Diệm, who became the first president of the anti-communist South Vietnam (Republic of Vietnam). He rose to become the deputy chief of staff in the Army of the Republic of Vietnam (ARVN), but his record of political loyalty was called into question. In 1960, during an attempted coup by rebel paratroopers, Khánh jumped over the walls of the Independence Palace and joined Diệm during the siege, trying to negotiate an end to the stand-off with the rebels. Khánh parleyed with the rebels long enough for loyal forces to arrive from the outside the capital to suppress the uprising, but his critics contended that he was waiting to see which side would gain the upper hand and was not committed to Diệm. In any case, Diệm then promoted him to be the commander of II Corps. In his younger days, Khánh had joined the Việt Minh but then defected to the French colonial army after a year. Khánh claimed that he had left the Viet Minh because of its communist inclinations, but critics claimed that he was simply switching sides because the French-backed State of Vietnam offered him more opportunities for advancement.
2