You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
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: 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-Lo 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 (18941973) 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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Solution: 1
Why? The question refers to the 704th unit and task about war which is decribed by Passage 1.

New input: Question: How many terms as a senator did Robert Kean's father serve? Passage 1:The first inhabitants were the Ahrensburg culture (11th to 10th millennia BC), which was a late Upper Paleolithic culture during the Younger Dryas, the last period of cold at the end of the Weichselian glaciation. The culture is named after the village of Ahrensburg, north-east of Hamburg in the German state of Schleswig-Holstein, where wooden arrow shafts and clubs have been excavated. The earliest traces of human occupation in Norway are found along the coast, where the huge ice shelf of the last ice age first melted between 11,000 and 8,000 BC. The oldest finds are stone tools dating from 9,500 to 6,000 BC, discovered in Finnmark (Komsa culture) in the north and Rogaland (Fosna culture) in the south-west. However, theories about two altogether different cultures (the Komsa culture north of the Arctic Circle being one and the Fosna culture from Trndelag to Oslofjord being the other) were rendered obsolete in the 1970s.
Passage 2:It was the 12th New Zealand Grand Prix, doubled as the opening round of the 1965 Tasman Series. The race attracted 19 starters, including several overseas based drivers and teams. A large contingent of cars from Australia competed, including Frank Gardner competing for Alec Mildren Racing. Lex Davison and Leo Geoghegan brought across their own teams, while 1962 Formula One world champion, British racer Graham Hill race a Brabham for David McKay's Scuderia Veloce team. Star attraction though was the appearance of Team Lotus with their lead driver, 1963 World Champion, Jim Clark. Local honour was upheld by Bruce McLaren, who in an early iteration of the later McLaren team brought a pair of factory supported Coopers to race with American racer, the 1961 World Champion Phil Hill as his number two. The race was won by Graham Hill, his first victory in the NZGP. Gardner finished second to be the first 'antipodean' while first New Zealander was domestic series racer Jim Palmer in a career highlight as Brabham racing cars clean swept the podium.
Passage 3:Kean was born September 28, 1893, in Elberon, New Jersey. His father, Hamilton Fish Kean (18621941), was a United States Senator from New Jersey and his son, Thomas Kean, served two terms as the Governor of New Jersey. Robert Kean was the great-great-grandson of John Kean, a Delegate to the Continental Congress from South Carolina (17561795). His uncle, John Kean (18521914), was also a United States Senator from New Jersey. His grandson, Thomas Kean, Jr., is presently the Minority Leader of the New Jersey State Senate. His mother, Katherine Taylor Winthrop (18661943), was a descendant of John Winthrop, a wealthy English Puritan lawyer and one of the leading figures in the founding of the Massachusetts Bay Colony, the first major settlement in what is now New England after Plymouth Colony. Winthrop led the first large wave of migrants from England in 1630 and served as governor for 12 of the colony's first 20 years of existence. Kean is also a descendant of William Livingston, the first Governor of New Jersey.

Solution:
3