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 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: How many different directors did Prada work with in 1976 and 1977? Passage:When Jaya Prada was a teenager, she performed a dance at her school's annual function. A film director in the audience offered her a three-minute dance number in the Telugu film Bhoomi Kosam. She was hesitant, but her family encouraged her to accept it. She was paid only 10 rupees for her work in the film, but the rushes of those three minutes of film were shown to the major figures of the Telugu film industry. Major filmmakers offered her starring roles in quality films, and she accepted them. She became a huge star in 1976 with major hit films. Director K. Balachander's black-and-white film Anthuleni Katha (1976) showcased her dramatic skills; K. Viswanath's color film Siri Siri Muvva (1976) showed her playing a mute girl with excellent dancing skills; and her title role as Sita in the big-budget mythological film Seetha Kalyanam confirmed her versatility. In 1977, she starred in Adavi Ramudu, which broke box office records and which permanently cemented her star status. The song "Aaresukoboyi Paresukunnanu" performed by Prada and co-star N.T. Rama Rao became a mass hit. Important filmmakers were casting her and repeating her in their films. Filmmaker Vijay introduced her to Kannada cinema in his 1977 super-hit movie Sanadi Appanna alongside Kannada matinee idol Raj Kumar. The movie is also known to be the only movie to feature shehnai rendition by Ustad Bismillah Khan. Jaya Prada repeated her successful pairing with Rajkumar in films such as Huliya Halina Mevu (1979), Kaviratna Kalidasa (1983) and Shabdavedhi (2000). In 1979, K. Balachander repeated her in the Tamil film Ninaithale Inikkum opposite Kamal Haasan and Rajinikanth in which she played a terminally-ill patient. She continued to act in more films in Telugu opposite actors such NTR, ANR, Krishna, Krishnam Raju and Sobhan Babu throughout the 70s and 80s. K. Viswanath remade Siri Siri Muvva (1976) in Hindi as Sargam, introducing Jayaprada to Bollywood in 1979. The film was successful and she became a star there as well. She earned her first Filmfare nomination as Best Actress but couldn't capitalize on her success since she couldn't speak Hindi.
 Links: a. Adavi Ramudu (1977 film) b. Filmfare c. Shehnai d. Anthuleni Katha
Example Output: d

Example Input: Question: How many different countries are the Dinaric Alps in? Passage:Vranica is a mountain range in the Dinaric Alps of central Bosnia and Herzegovina, located between the town of Gornji Vakuf in the west and the town of Fojnica in the east, within the territory of the Federation. The highest peak is Nadkrstac at . Geologically, the Vranica range is part of the Dinaric Alps and formed largely of secondary and tertiary sedimentary rock, mostly limestone. Notable peaks are Nadkrstac (2110 m.), Locika (2106 m.), Rosinj (2059 m.) and Scit (1949 m.). Thick shrubs of Pinus Mugo replace mixed forest -mostly beech- above 1400 m. The typical karst characteristics of the nearby Herzegovina mountains is relatively absent in Vranica, which has relatively abundant water sources. Streams that source from these mountains are the Dragača in the east, the Vrbas in the west. 
 Links: a. Pine b. Fojnica c. Dinaric Alps d. Fojnica
Example Output:
c

