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: How many people did Arnstadt command as a company commander of the 6th border company in Dermbach? Passage:In June 1949, Arnstadt registered for service with the Volkspolizei, the police force of the Soviet Occupation Zone, becoming an Anwärter der VP (police cadet) with the Kasernierte Volkspolizei in Gotha. In March 1950, Arnstadt was appointed to the German Border Police (Deutsche Grenzpolizei) in Dermbach, patrolling the Inner German border with West Germany. In 1952, Arnstadt failed his first attempt to become an officer at the police school in Sondershausen. In 1953, his marriage ended in divorce, with his two children Veronika and Uwe staying with the mother, and remarried shortly after. In 1954, Arnstadt passed his officer training at Sondershausen and was appointed the rank of Unterleutnant, and the following year was promoted to lieutenant. Arnstadt functioned as a recruiter for the German Border Police until 1957 when he was appointed as a company commander of the 6th border company in Dermbach. Arnstadt was responsible for a section of the border at Wiesenfeld, a region of Bezirk Suhl in the Rhön Mountains at the westernmost point of the Warsaw Pact. Arnstadt's section contained the highly-strategic Fulda Gap, which aroused the special interest of NATO, and a short distance from the US Army's Observation Post Alpha. Arnstadt moved with his wife to Wiesenfeld and in April 1957 became an unofficial collaborator (Geheimer Informator) of the Ministry for State Security (Stasi) until this relationship was ended fourteen months later. 
 Links: a. Company commander b. Inner German border c. Dermbach d. Kasernierte Volkspolizei
Example Output: a

Example Input: Question: When did the event where  Frank Alberry won a Distinguished Conduct Medal end? Passage:Frank Alberry, DCM (29 September 1892 – 23 January 1968) was an Australian soldier and airman who had a varied military career. Born in Hobart, he served in the Welch Regiment of the British Army before the First World War, but deserted. He joined up again in the early days of the First World War, and went on to serve with the 8th Battalion of the Australian Imperial Force. After service at Gallipoli, he joined the British Expeditionary Force in France. He won a Distinguished Conduct Medal at the Battle of Pozières, but lost a lower leg in the process. Alberry took the extraordinary step of personally petitioning King George V for permission to transfer to the Flying Corps, and subsequently became a flying ace credited with seven aerial victories. Alberry returned to service during the Second World War as a recruiter.
 Links: a. Distinguished Conduct Medal b. Battle of Pozières c. 8th Battalion (Australia) d. World War II
Example Output: b

Example Input: Question: Which of the two successful crime television show on NBC was the longest running? Passage:In 1979, Mann wrote a 180-page draft of Heat. He re-wrote it after making Thief in 1981 hoping to find a director to make it and mentioning it publicly in a promotional interview for his 1983 film The Keep. In the late 1980s, he offered the film to his friend, film director Walter Hill, who turned him down. Following the success of Miami Vice and Crime Story, Mann was to produce a new crime television show for NBC. He turned the script that would become Heat into a 90-minute pilot for a television series featuring the Los Angeles Police Department Robbery–Homicide division, featuring Scott Plank in the role of Hanna and Alex McArthur playing the character of Neil McCauley, renamed to Patrick McLaren. The pilot was shot in only nineteen days, atypical for Mann. The script was abridged down to almost a third of its original length, omitting many subplots that made it into Heat. The network was unhappy with Plank as the lead actor, and asked Mann to recast Hanna's role. Mann declined and the show was canceled and the pilot aired on August 27, 1989 as a television film entitled L.A. Takedown. which was later released on VHS and DVD in Europe.
 Links: a. Miami Vice b. Crime Story (American TV series) c. Alex McArthur d. Miami Vice
Example Output:
a