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 square miles is the town where the route from West Virginia split? Passage:By 1947, present Interstate 70 across Pennsylvania was included in the planned Interstate Highway System. The route from West Virginia split at Washington, with one branch heading northeast to meet the Pennsylvania Turnpike near Pittsburgh and the other heading east, bypassing Pittsburgh to the south (via a planned bypass of Pennsylvania Route 71) to the New Stanton interchange. The piece south from the Breezewood interchange into Maryland was also in the network. The route between US 30 in Breezewood and US 522 in Warfordsburg was originally known as Pennsylvania Route 126. In 1957, preliminary numbers were assigned; the longer route via Pittsburgh (now Interstate 79 and Interstate 376) became the main line of I-70, while the southern bypass (now I-70) became Interstate 70S. The section of present-day I-70 between PA 519 near Washington and New Stanton was built as a four-lane divided highway known as the "Express Highway"; this road was assigned the temporary PA 71 Alternate designation in 1957 and would be designated as I-70S following the completion of additional connecting roads in the Interstate Highway System. On July 15, 1960, I-70 was designated onto the Penn-Lincoln Parkway. A southern extension of Interstate 79 (which had previously only run from Erie south to Pittsburgh) to Charleston, West Virginia in 1963 resulted in changes to I-70. On February 26, 1964, as part of the formation of Interstate 76 (east of downtown Pittsburgh), AASHTO approved a rerouting of I-70 along I-70S. The former I-70 became I-79 from Washington to downtown Pittsburgh and I-76 to and along the Turnpike to New Stanton. This brought the routing of I-70 to its present form.
 Links: a. Charleston, West Virginia b. Washington, Pennsylvania c. Pittsburgh d. Interstate 79
Example Output: b

Example Input: Question: Was the person whose memoirs were translated by Obolensky a Russian general? Passage:Born in 1909 in the family of Orthodox princes Obolensky, from 1925 in exile in France, where, together with his father Nikolai Leonidovich Obolensky adopted Catholicism. He went to the Benedictines, where studied philosophy, and in 1943 he defended his doctoral degree from Pontifical Atheneum of St. Anselm in Rome. From 1935 he studied at Russicum. Ordained priest in 1940, Obolensky was sent to Paris, where he taught at Saint George Boarding in Meudon. He was also a member of the Congress of Russian Catholics in 1950 in Rome. Obolensky taught courses on the history of Russian literature and philosophy in Rome, Meudon and Bergamo. He worked as an expert on the Soviet Union in NATO. He was also author of books on the Soviet economy, translated the correspondence of Joseph Stalin, Franklin Roosevelt and Winston Churchill, and the memoirs of Georgy Zhukov and was engaged in the Soviet dissident literature. He died in 1992 in Belgium, the home of his sister.
 Links: a. Franklin D. Roosevelt b. Georgy Zhukov c. Winston Churchill d. Meudon
Example Output: b

Example Input: Question: How long did the period of China when Ji was an official last? Passage:Jiang Ji (died 18 May 249), courtesy name Zitong, was an official and military general of the state of Cao Wei during the Three Kingdoms period of China. Born in the late Eastern Han dynasty, Jiang Ji started his career as a low-level official in his native Yang Province before becoming a subordinate of Cao Cao, the warlord who controlled the central government towards the end of the Eastern Han dynasty. After the end of the Eastern Han dynasty, he served in the state of Cao Wei through the reigns of the first three emperors – Cao Pi, Cao Rui and Cao Fang – and held various appointments in the military before rising to Grand Commandant, one of the top positions in the central government. During his service in Wei, he was known for being candid in giving advice to the emperor on various issues, including consolidating power, halting labour-intensive construction projects, and officials' abuses of power. In February 249, he joined the regent Sima Yi in staging a successful coup d'état against his co-regent Cao Shuang, but died from illness a few months later.
 Links: a. Yang Province b. Three Kingdoms c. Cao Fang d. Yang Province
Example Output:
b