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.

Ex Input:
Question: Who was the head coach for Ajax Youth Academy when Jozefzoon joined? Passage:A Winger and attacking midfielder, Jozefzoon began his career with spells at CTO '70 and AFC. He joined the Ajax Youth Academy in 2006 and signed a three-year professional contract in June 2008. Jozefzoon won his maiden call into the first team squad for the opening match of the 201011 Eredivisie season versus FC Groningen and remained an unused substitute during the 22 draw. He made his senior debut six days later, replacing Urby Emanuelson at half time during a 42 win over SBV Vitesse. He scored his only goal for the club in a 50 KNVB Becker third round win over MVV Maastricht on 22 September 2010. After five appearances during the 201011 season, Jozefzoon signed a one-year contract extension in June 2011, but spent the 201112 season away on loan and was released at the end of the season.
Links: a. SBV Vitesse b. SBV Vitesse c. Ajax Youth Academy d. Ajax Youth Academy

Ex Output:
c

Ex Input:
Question: How many years did the owner of the private observatory live? Passage:It would seem that Gill's interests lay elsewhere since after a few years he sold the business, and then spent time equipping Lord Lindsay's private observatory at Dun Echt, Aberdeenshire. In 1874, Gill joined the expedition to Mauritius to observe the transit of Venus. Three years later he went to Ascension Island to observe a near approach of Mars and to calculate its distance. While carrying out these laborious calculations, he was notified of his appointment to the Cape Observatory, which, over the following 27 years he was to refurbish completely, turning it into a first-rate institution. Gill was a meticulous observer and had a flair for getting the best out of his instruments. His solar parallax observations with a heliometer and his calculations of distances to the nearer stars, are testimony to his outstanding work. He recruited Robert Innes to the Cape Observatory.
Links: a. South African Astronomical Observatory b. Aberdeenshire (historic) c. James Lindsay, 26th Earl of Crawford d. South African Astronomical Observatory

Ex Output:
c

Ex Input:
Question: How long was Ron Hughes Commander? Passage:Dunstan was then posted to the 1st Battalion, Royal Australian Regiment (1 RAR) as second-in-command in 1953. He then saw service in Korea including a period as Military Assistant to the Commander in Chief of the British Commonwealth Forces Korea, and was appointed a Member of the Order of the British Empire in the 1954 New Year Honours. Between May 1964 and February 1965, Dunstan commanded 1 RAR, before later holding an appointment at the 1st Recruit Training Battalion. Having reached the rank of colonel, in early 1968 he was deployed to Vietnam as deputy commander of the 1st Australian Task Force (1 ATF). He took over from Brigadier Ron Hughes as Commander of the 1 ATF on 21 May 1968 during the Battle of CoralBalmoral. For his services during this battle, he was appointed a Commander of the Order of the British Empire in 1969.
Links: a. 1st Battalion, Royal Australian Regiment b. Order of the British Empire c. Brigadier d. 1954 New Year Honours

Ex Output:
b