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.

Ex Input:
Question: Who was in charge at Princeton University the year Barschall graduated from that school? Passage:Barschall was born as Heinrich Hermann Barschall in Berlin, Germany; his father was a patent attorney who had received a Ph.D. in chemistry after studying with Nobel Laureates Emil Fischer and Fritz Haber. After beginning study in several universities in Germany, he emigrated to the United States in 1937 during the early Holocaust period; though raised as a Lutheran, he had some Jewish ancestry. He received his Ph.D. from Princeton University in 1940 under the direction of Rudolf Ladenburg; he also worked closely with John A. Wheeler. After a suggestion by Niels Bohr, he carried out in only a few days with fellow graduate student Morton H. Kanner the first demonstration of fission by fast neutrons and thorium and uranium. His thesis was on the interaction of fast neutrons with helium. In a paper with John A. Wheeler he reported the discovery of spin-orbit coupling in neutron scattering.
 Links: a. Emil Fischer b. Princeton University c. Jews d. John Archibald Wheeler

Ex Output:
b


Ex Input:
Question: Which aircraft had a longer operational lifespan in the Royal Canadian Air Force between the McDonnell CF-101 Voodoo and the Avro CF-100 Canuck? Passage:The McDonnell CF-101 Voodoo was an all-weather interceptor aircraft operated by the Royal Canadian Air Force and the Canadian Forces between 1961 and 1984. They were manufactured by the McDonnell Aircraft Corporation of St. Louis, Missouri for the United States Air Force (as F-101s), and later sold to Canada. CF-101s replaced the obsolete Avro CF-100 Canuck in the RCAF's all-weather fighter squadrons. The Voodoo's primary armament was nuclear AIR-2A Genie unguided air-to-air rockets, and there was significant political controversy in Canada about their adoption. Although they never fired a weapon in wartime, the CF-101 served as Canada's primary means of air defence from Quick Reaction Alert facilities at Canadian airbases. The CF-101s were retired in the 1980s and replaced with McDonnell Douglas CF-18 Hornet fighters. Many examples are preserved in museums and parks in Canada and the United States.
 Links: a. Avro Canada CF-100 Canuck b. Interceptor aircraft c. Interceptor aircraft d. Royal Canadian Air Force

Ex Output:
a


Ex Input:
Question: Who was the mayor of St. Charles when Asche was born? Passage:Asche was born on June 30, 1990 in St. Charles, Missouri to Todd and Julie Asche; he has a brother named Tyler. He grew up playing baseball, which he started playing with his father and brother in the yard around age five, and football, but he quit playing football in his freshman year of high school. He attended Fort Zumwalt West High School in O'Fallon, Missouri. Playing for the school's baseball team, he had a .425 batting average across his career and batted .512 in his senior season. He then enrolled at the University of Nebraska, where he played college baseball for the Nebraska Cornhuskers. In 2011, Asche's junior year, he had a .327 batting average. His 12 home runs led the Big 12 Conference, while his 56 runs batted in (RBIs) placed him second in the conference. He was named a second-team All-American. While at Nebraska, he majored in economics and maintained a grade point average (GPA) of 3.407. Because of his strong grades, he earned placement on the Big 12 Conference Commissioner's Honor Roll, a distinction bestowed upon student-athletes that achieve a GPA of 3.0 or greater, for five of his college semesters.
 Links: a. St. Charles, Missouri b. Big 12 Conference c. All-America d. Big 12 Conference

Ex Output:

a