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: At what age did Litto Nebbia write La balsa? Passage:"La balsa" (; Spanish for "the raft") is the debut single by the Argentine band Los Gatos, released on July 3, 1967 on Vik, a subsidiary of RCA Victor. Formed in 1967 after the disbandment of Los Gatos Salvajes, Los Gatos were the house band of the bar La Cueva, which became a popular meeting place for rock enthusiasts and the birthplace of Argentine rock—known locally as rock nacional (Spanish for "national rock"). During the mid-to-late 1960s, Buenos Aires was experiencing a cultural blossoming characterized by innovations in modern art, literature and cinema, largely driven by a burgeoning youth subculture that adhered to the countercultural phenomenon of the decade. The underground had its center in La Cueva, Plaza Francia and the Torcuato di Tella Institute, and identified with British Invasion music and the sexual revolution. "La balsa" was written by Litto Nebbia—lead vocalist of the band—and Tanguito (credited as Ramsés) on May 2, 1967, in the men's toilet of La Perla de Once, another bar frequented by the group. At the time, Argentina was under a military dictatorship led by Juan Carlos Onganía, which regularly imprisoned and persecuted these young bohemians.
 Links: a. Los Gatos Salvajes (band) b. Juan Carlos Onganía c. Juan Carlos Onganía d. Litto Nebbia
Example Output: d

Example Input: Question: How long had the Royal Canadian Air Force existed the year that the McDonnell CF-101 Voodoo began being operated by them? Passage:The McDonnell CF-101 Voodoo was an all-weather interceptor aircraft operated by the Royal Canadian Air Force and the Canadian Forces between 1961 and 1984. They were manufactured by the McDonnell Aircraft Corporation of St. Louis, Missouri for the United States Air Force (as F-101s), and later sold to Canada. CF-101s replaced the obsolete Avro CF-100 Canuck in the RCAF's all-weather fighter squadrons. The Voodoo's primary armament was nuclear AIR-2A Genie unguided air-to-air rockets, and there was significant political controversy in Canada about their adoption. Although they never fired a weapon in wartime, the CF-101 served as Canada's primary means of air defence from Quick Reaction Alert facilities at Canadian airbases. The CF-101s were retired in the 1980s and replaced with McDonnell Douglas CF-18 Hornet fighters. Many examples are preserved in museums and parks in Canada and the United States.
 Links: a. AIR-2 Genie b. Royal Canadian Air Force c. McDonnell Douglas CF-18 Hornet d. Royal Canadian Air Force
Example Output: b

Example Input: Question: In what year did Rosalind Harris perform the role of Mama Rose? Passage:Harris also had an extensive theatre career, having performed in leading roles in many musicals in Off Broadway, regional theater and stock. Her credits include: Elsie in Horatio (Arena Stage), Jenny Hill in Major Barbara (American Shakespeare Festival)/& understudy to Jane Alexander, Aldonza in Man of La Mancha, Mama Rose in Gypsy, Leona Samish in Do I Hear a Waltz? (Equity Library Theatre), 10 productions of Funny Girl, as Fanny Brice (her favorite production, at Chateau DeVille Dinner Theatre, was directed by Christopher Hewett, along with original Broadway Musical Director, Milton Rosenstock), and, Off Broadway, as Dora in The Rise of David Levinsky (American Jewish Theatre), Harris made many television commercials as well, and her spot as a "female doctor" in a Mogen David Wine commercial won a Clio Award. In 1993, she was nominated for a MAC Award for her work in the cabaret show, Hollywood Opera, at Don't Tell Mamas, in New York City, written by and also starring Barry Keating.
 Links: a. Off-Broadway b. Fanny Brice c. Man of La Mancha d. Gypsy (musical)
Example Output:
d