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: Is Prague the capital of a country? Passage:In the months following up to the September 11 attacks, officials at the Czech Interior Ministry asserted that Atta made a trip to Prague on April 8, 2001, to meet with an Iraqi intelligence agent named Ahmed Khalil Ibrahim Samir al-Ani. This piece of information was passed on to the FBI as "unevaluated raw intelligence". Intelligence officials have concluded that such a meeting did not occur. A Pakistani businessman named Mohammed Atta had come to Prague from Saudi Arabia on May 31, 2000, with this second Atta possibly contributing to confusion. The Egyptian Mohamed Atta arrived at the Florenc bus terminal in Prague, from Germany, on June 2, 2000. He left Prague the next day, flying on Czech Airlines to Newark, New Jersey, U.S. In the Czech Republic, some intelligence officials say the source of the purported meeting was an Arab informant who approached the Czech intelligence service with his sighting of Atta only after Atta's photograph had appeared in newspapers all over the world. United States and Czech intelligence officials have since concluded that the person seen with Ani was mistakenly identified as Atta, and the consensus of investigators has concluded that Atta never attended a meeting in Prague.
Links: a. Prague b. Prague c. Germany d. Prague
Example Output: a

Example Input: Question: How many members did No. 11 Group have during the years of the Blitz? Passage: the Second World War, the station was very active during the Battle of Britain and the Blitz in 194041 in No. 12 Group (controlled from RAF Watnall in Nottingham) as it was the main fighter station for a lot of the southern East Midlands, and fighters from the station would often patrol as far as Birmingham. During the Battle of Britain many squadrons were rotated through Wittering to spells in the south of England with No. 11 Group that was bearing the brunt of the battle. With many of the Luftwaffe raids during the Blitz taking part at night, Wittering-based squadrons were instrumental in the development of night combat techniques. These included the use of the Turbinlite aircraft which replaced the nose with a powerful searchlight insulated in the nose of Havocs and Bostons. In April 1943 No. 141 Squadron were moved in, operating de Havilland Mosquitoes. 1943 also saw the station host 2 USAAF squadrons, albeit temporarily: 63 Fighter Squadron USAAF with its P47s operated from Wittering between January and March before moving to RAF Horsham St Faith; 55 Fighter Squadron operated its P38s and P51s from Wittering between August and March 1944 before moving to nearby RAF Kingscliffe.
Links: a. No. 11 Group RAF b. Birmingham c. Birmingham d. 63rd Fighter Squadron
Example Output: a

Example Input: Question: What is the name of the first album the Swedish pop group ABBA ever released? Passage:The Definitive Collection is a 2001 compilation album of all the singles released by Swedish pop group ABBA. It consisted of two discs: the first featuring the singles from 197279 ("People Need Love" to "Does Your Mother Know"), and the second including the singles from 197982 ("Voulez-Vous" to "Under Attack"), with the tracks being listed in chronological order. The main exception is the track "Thank You for the Music", which, despite being written and recorded in 1977, was in fact released as a single (primarily in the UK) in 1983 after the band had split up. It appears on disc two, along with two bonus tracks, "Ring Ring" (1974 UK single remix), and "Voulez-Vous" (1979 US promo extended remix). The Australian version of The Definitive Collection adds a further two bonus tracks: "Rock Me" and "Hasta Manana". The 1974 remix of "Ring Ring" is the first appearance on CD of this version mastered from the original master tape, after the UK single master tapes had been returned to Polar Music by the former UK licensees, Epic Records. The track's previous appearance on CD, in a 1999 singles boxed set, was mastered from a vinyl single.
Links: a. ABBA b. People Need Love c. Compilation album d. Epic Records
Example Output:
a