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 years were there between the end of the British Burma Campaign and the start of the Battle of Na San? Passage:The First Indochina War had raged, as guerrilla warfare, since 19 December 1946. From 1949, it evolved into conventional warfare, due largely to aid from the communists of the People's Republic of China ("PRC") to the north. Subsequently, the French strategy of occupying small, poorly defended outposts throughout Indochina, particularly along the Vietnamese-Chinese border, started failing. Thanks to the terrain, popular support for August Revolution and support for decolonization from bordering China and the U.S.S.R., the Viet Minh had succeeded in turning a "clandestine guerrilla movement into a powerful conventional army", following asymmetric warfare theory laid by Mao Tse Tung, something which previously had never been encountered by the western colonial powers. In October 1952, fighting around the Red River Delta spread into the Thai Highlands, resulting in the Battle of Nà Sản, at which the Viet Minh were defeated. The French used the lessons learned at Nà Sản – strong ground bases, versatile air support, and a model based on the British Burma Campaign – as the basis for their new strategy. The Viet Minh, however, remained unbeatable in the highland regions of Vietnam, and the French "could not offset the fundamental disadvantages of a roadbound army facing a hill and forest army in a country which had few roads but a great many hills and forests".
 Links: a. China b. On Guerrilla Warfare c. Battle of Nà Sản d. China
Example Output: c

Example Input: Question: In what country did Cameron accept a chair of philosophy? Passage:Cameron was born at Glasgow and received his early education in his native city. After having taught Greek in the university for twelve months, he removed to Bordeaux, where he was soon appointed a regent in the college of Bergerac. He did not remain long at Bordeaux, but accepted the offer of a chair of philosophy at the Academy of Sedan, where he passed two years. He then returned to Bordeaux, and in the beginning of 1604 he was nominated one of the students of divinity who were maintained, at the expense of the church, and who for the period of four years were at liberty to prosecute their studies in any Protestant seminary. During this period he acted as tutor to the two sons of the chancellor of Navarre. They spent one year at Paris, and two at Geneva, whence they removed to Heidelberg. In this university, on 4 April 1608, he gave a public proof of his ability by maintaining a series of theses, De triplici Dei cum Homine Foedere, which were printed among his works. The same year he was recalled to Bordeaux, where he was appointed the colleague of Dr Gilbert Primrose; and when Francis Gomarus was removed to Leiden, Cameron, in 1618, was appointed professor of divinity at the Academy of Saumur, the principal seminary of the French Protestants. 
 Links: a. Academy of Saumur b. Greek language c. University d. Academy of Sedan
Example Output: d

Example Input: Question: How many songs total did Clarkson perform on the Breakaway World Tour? Passage:Clarkson has performed the song in eight of her concert tours. First, she performed the song on the Breakaway World Tour, Hazel Eyes Tour, and the Addicted Tour (2005–06). Later, Clarkson performed the track on the My December Tour (2007–08). She also performed the song on the 2 Worlds 2 Voices Tour (2008), a co-headlining concert tour with Reba McEntire. It was the first Clarkson song to be performed. Later, she performed the song on the All I Ever Wanted Tour (2009–10). On the Stronger Tour (2012), Clarkson performed the song as part of a medley, with "The Trouble With Love Is", "How I Feel" and "I Want You". When Clarkson performed the song on her most recent tour, the 12th Annual Honda Civic Tour, where she was a special guest for Maroon 5, she and her music director changed the arrangement to make it sound more jazzy. For her Piece by Piece Tour (2015) Clarkson mashes the song up with "Uptown Funk" by Mark Ronson and Bruno Mars.
 Links: a. Stronger Tour b. Uptown Funk c. The Breakaway Tour d. Stronger Tour
Example Output:
c

