In this task, you're given a question, a context passage, and four options which are terms from the passage. After reading a passage, you will get a brief understanding of the terms. Your job is to determine by searching and reading further information of which term you can answer the question. Indicate your choice as 'a', 'b', 'c', or 'd'. If you think more than one option is plausible, choose the more probable option to help you answer the question.

Example Input: Question: Who did the Bears defeat in their 1963 Super Bowl win? Passage:The Bears won fifteen games, as the 49ers had the year before, and won their first twelve before losing to the Miami Dolphins to deny a perfect season. The Bears' defense was ranked first in the league and only allowed 198 total points (an average of 12.4 points per game). The Bears won the NFC Central Division by seven games over the second place Green Bay Packers and earned the NFC's top seed and home field advantage throughout the playoffs at Soldier Field. In their two playoff games against the New York Giants and Los Angeles Rams, the Bears outscored their opponents 45–0 and became the first team to record back-to-back playoff shutouts. Then, in Super Bowl XX in New Orleans against the New England Patriots, the Bears set several more records. First, their 46 points broke the record that had been set by the Los Angeles Raiders in 1984 with 38 and tied by the 49ers the following year. Their 36-point margin of victory topped the 29-point margin of victory that the Raiders had put up in Super Bowl XVIII and stood as a record until the 49ers won Super Bowl XXIV, also in New Orleans, by 45 points over the Denver Broncos. It was the Bears' first NFL World Championship title since 1963.
 Links: a. 1963 NFL season b. 1985 Los Angeles Rams season c. Super Bowl XX d. 1985 Los Angeles Rams season
Example Output: a

Example Input: Question: What city was the game held where Beccacece's team beat O'Higgins 8-1? Passage:On 24 January, in his second league game since his debut for this competition at the bench (a 1–1 away draw with Deportes Antofagasta), Beccacece impressed following the team’s 8–1 home thrash over O'Higgins at the Estadio Nacional. After of that great victory nevertheless the team reaped three draws and one loss against Palestino (2–1). During February’s first days, the team was eliminated of the Copa Libertadores first stage by Uruguay’s River Plate F.C., which was his first failure and it meant being the target of criticism from the press and the team’s supporters. On 28 February, the 4–1 away victory over Cobresal would be a balm of the team’s moment. Following a 0–0 draw with Unión Española and two losses (3–1 with Universidad de Concepción as local and 5–4 against Santiago Wanderers as visitors), he back to draw, now in the Chilean football derby with Colo-Colo, which was again a goalless where both teams were criticized for its game level. Finally, Beccacece would end in the tenth place with three wins, seven draws and five losses and his continuity was heavily questioned during the Copa América Centenario break.
 Links: a. Estadio Nacional Julio Martínez Prádanos b. 2016 Copa Libertadores first stage c. C.D. Antofagasta d. 2016 Torneo Clausura (Chile)
Example Output: a

Example Input: Question: How many soldiers made up the Australian Imperial Force the year Holden enlisted with them? Passage:Holden enlisted in the Australian Imperial Force on 26 May 1915, and was posted to the 4th Light Horse Brigade as a private. He departed for Egypt aboard the transport A29 Suevic on 13 June. Serving as a driver first in the Middle East and then on the Western Front, his mechanical ability and sense of adventure led him to volunteer for the Australian Flying Corps (AFC) in December 1916. After qualifying as a pilot in England, he was commissioned a lieutenant and posted to No. 2 Squadron. Commanded by Major Oswald Watt, No. 2 Squadron's personnel included many former Lighthorsemen, as well as mechanics from the AFC's first combat formation, the Mesopotamian Half Flight. The force trained extensively in England commencing in January 1917, before deploying to the Western Front that September. Holden was involved in the AFC's first day of combat in France; just after noon on 2 October, in the vicinity of Saint-Quentin, he and his wingman engaged a German two-seater that managed to escape.
 Links: a. First Australian Imperial Force b. Mesopotamian Half Flight c. Saint-Quentin, Aisne d. Oswald Watt
Example Output:
a