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.

Input: Consider Input: Question: How long had The Observer been operating as a going concern the year Harrisson started working there as a radio critic? Passage:During the Second World War Harrisson continued directing Mass-Observation and was radio critic for The Observer from May 1942 until June 1944. For much of this time he was in the army and gave up reviewing on leaving the UK. After service in the ranks he was commissioned as a second lieutenant in the Reconnaissance Corps on 21 November 1943. He had been recruited (some sources say by a confusion of names, despite his apparent suitability) for a plan to use the native peoples of Borneo against the Japanese. He was attached to Z Special Unit (also known as Z Force), part of the Services Reconnaissance Department (SRD: a branch of the combined Allied Intelligence Bureau in the South West Pacific theatre). On 25 March 1945, he was parachuted with seven Z Force operatives from a Consolidated Liberator onto a high plateau occupied by the Kelabit people. An autobiographical account of this operation (SEMUT I, one of four SEMUT operations in the area) is given in World Within (Cresset Press, 1959); there are also reports – not always flattering – from some of his comrades. His efforts to rescue stranded American airmen shot down over Borneo are a central part of "The Airmen and the Headhunters", an episode of the PBS television series Secrets of the Dead. The recommendation for his Distinguished Service Order which was gazetted on 6 March 1947 (and dated 2 November 1946) describes how from his insertion until 15 August 1945 the forces under his command protected the flank of Allied advances, and caused severe disruption to Japanese operations.
 Links: a. Z Special Unit b. The Observer c. Kelabit people d. Second lieutenant

Output: b


Input: Consider Input: Question: How many NBA championships have been won by the team that Payton was traded to on February 24, 2005? Passage:Prior to the 2004–05 season, the Lakers traded Payton and Rick Fox to the Boston Celtics for center Chris Mihm, small forward Jumaine Jones and point guard Chucky Atkins. While Payton expressed displeasure with the trade, he ultimately did report to Boston and began the 2004–05 season as the Celtics' starting point guard. On February 24, 2005 Payton was traded to the Atlanta Hawks in a deal that brought former Celtic Antoine Walker back to Boston. The Hawks then waived Payton immediately following the trade, and he returned a week later to Boston as a free agent. Payton started all 77 games he played for Boston and averaged 11.3 points per game and 6.1 assists as the Celtics won the Atlantic Division before losing in the first round to the Indiana Pacers.
 Links: a. Boston Celtics b. Atlanta Hawks c. Indiana Pacers d. Antoine Walker

Output: b


Input: Consider Input: Question: How large was Princeton's endowment 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. Jews b. Emil Fischer c. Thorium d. Princeton University


Output: d