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 old was Arrigo Sacchi when Carbone moved to Milan? Passage:Carbone had a much travelled career, playing for ten different clubs. He began his youth career with Bari, making his professional debut with the club in Serie B during the 1988–89 season, earning promotion to Serie A. During his first season in Serie A, he broke into the starting line-up, making 26 appearances and scoring a goal against Inter at the San Siro stadium. In 1990, he moved to Milan at the request of manager Arrigo Sacchi. During his first season with the club, he made 21 appearances in Serie A, making his club debut on 9 September 1990, in a 1–0 home win over Genoa in Serie A. He also made his UEFA Champions League debut, scoring a goal against Club Bruges, and he started in Milan's European Supercup and Intercontinental Cup victories in 1990.
 Links: a. Genoa C.F.C. b. Arrigo Sacchi c. A.C. Milan d. Genoa C.F.C.
Example Output: b

Example Input: Question: Comparing the places Naipaul visited while writing his book, what is the difference in population between the two? Passage:Black & White is a non-fiction book written by Shiva Naipaul and published by Hamish Hamilton in the U.K. in 1980. It was published with the title Journey to Nowhere: A New World Tragedy in the U.S. The book is based on Naipaul's trip to Guyana in the aftermath of the Jonestown Massacre, and his subsequent trip to the United States, in which he explored links between the People's Temple and other groups and individuals. Naipaul attempted to connect Rev. Jim Jones, founder of the People's Temple, with disparate parts of California's counterculture, and Guyanese and other Third World governments and the revolutionary ideologies which supported them. Naipaul was highly critical of these and other movements, including black theology, the nascent New Age movement and EST, in as much as they helped, in his analysis, to create fertile ground for the People's Temple to flourish on the two continents. The book's US paperback cover tagline reads "How American ideas and ideologies led to the mass suicide of 900 people in Jonestown, Guyana."
 Links: a. Guyana b. Jonestown c. Liberation movement d. Shiva Naipaul
Example Output: a

Example Input: Question: When did the fight in which the 4th Mechanized Corps participate in as part of Steppe Front begin? Passage:In December 1942 the Corps gained a Guards title and became the 3rd Guards Mechanised Corps. It fought at the Battle of Kursk as part of Steppe Front. In June 1944, for Operation Bagration, it was assigned to Chernyakhovsky's 3rd Belorussian Front as part of a Cavalry Mechanized Group which also included 3rd Cavalry Corps and was tasked to hit Bogushevsk in conjunction with 5th Army and 39th Army. Its units included 64th Guards Heavy Tank Regiment, which operated IS-2 heavy tanks while fighting as part of the 1st Baltic Front in the Šiauliai ('Shaulay') area during July 1944. It was then moved to the Far East and took part in the invasion of Manchuria as part of the Transbaikal Front. The Corps, which gained the honorific Stalingrad-Krivorozhskaya, became 3rd Guards Mechanised Division in November 1945, and later 47th Guards Motor Rifle Division in 1957. It was finally disbanded on 27 November 1959 while serving with 5th Army in the Far East Military District at Dalnerechensk.
 Links: a. Battle of Kursk b. Steppe Front c. Battle of Kursk d. 3rd Belorussian Front
Example Output:
a