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: Are the two canals which were built in 1914 and 1930, and which are located in parallel to the Lippe, of equal length to each other? Passage:Historically, the preconditions for a change of the landscape started with the construction of the Cologne-Minden trunk line in the 1840s that connected the river Rhine settlements like Cologne with harbours and trade at the river Weser and so with the Lippe town Hamm, too. Moreover, this railway supported the coal and steel industry development in the northern Ruhr region. The hard coal mining that started in the middle of the 19th century in the Emscher catchment area developed in the following decades direction north and so to the Lippe catchment area, too, where from the 1860s on first problems from mining subsidence and drainage of polluted water appeared. The historical city of Hamm and the towns Lünen, Haltern and Dorsten were small settlements located at the Lippe but expanded with the establishing of hard coal mines starting around 1900. The industrialization caused huge water quality problems in the Lippe tributaries and the Lippe itself; therefore first in 1913 the Sesekegenossenschaft and later in 1926 the Lippeverband as water boards (“Wasserwirtschaftsverbände”) were established. Since 1914 the Datteln-Hamm Canal and 1930 the Wesel-Datteln Canal are located in parallel to the Lippe which is not navigable for mass transportation. The canals receive Lippe water or feed the Lippe (to improve dry weather flow) from an exchange facility in Hamm, operated by the Wasserverband Westdeutsche Kanäle.
 Links: a. Cologne-Minden trunk line b. Wasserverband Westdeutsche Kanäle c. Datteln-Hamm Canal d. Weser
Example Output: c

Example Input: Question: Who earned the bronze medal in the event where the Austrian athlete earned the gold? Passage:Sonja Henie of Norway won her third straight gold medal in the ladies' singles figure skating event, her last Olympic medal as she turned professional shortly after the Games. Karl Schäfer of Austria also successfully defended his men's singles figure skating title from Lake Placid. Sweden swept the medals in the cross-country 50 km, as did Norway in the Nordic combined. Norway's Ivar Ballangrud was the most successful athlete, winning three golds and a silver in speed skating and taking his career total to seven Olympic medals. Other multiple medal winners were Oddbjørn Hagen of Norway (one gold, two silvers), Ernst Baier of Germany (one gold, one silver), Joseph Beerli of Switzerland (one gold, one silver), Erik August Larsson of Sweden (one gold, one bronze), Birger Wasenius of Finland (two silvers, one bronze), Olaf Hoffsbakken of Norway (two silvers), Fritz Feierabend of Switzerland (two silvers) and Sverre Brodahl of Norway (one silver, one bronze).
 Links: a. Figure skating at the 1936 Winter Olympics – Men's singles b. Nordic combined at the 1936 Winter Olympics c. Fritz Feierabend d. Nordic combined at the 1936 Winter Olympics
Example Output: a

Example Input: Question: Was Granger or Taylor older in 1952? Passage:Metro-Goldwyn-Mayer (MGM) originally announced a remake of the 1925 silent film Ben-Hur in December 1952, ostensibly as a way to spend its Italian assets. Stewart Granger and Robert Taylor were reported to be in the running for the lead. Nine months later, MGM announced it would make the film in CinemaScope, with shooting beginning in 1954. In November 1953, MGM announced it had assigned producer Sam Zimbalist to the picture and hired screenwriter Karl Tunberg to write it. Zimbalist was chosen because he had produced MGM's Best Picture-nominated Christians-and-lions epic Quo Vadis in 1951. The studio then announced in July 1954 that production would start in March 1955 with 42 speaking parts and 97 sets. MGM said Sidney Franklin would direct, that the script by Tunberg was finished, that shooting would occur in Rome and in Spain, and that Marlon Brando was up for the lead. In September 1955, Zimbalist, who continued to claim that Tunberg's script was complete, announced that a $7 million, six-to-seven month production would begin in April 1956 in either Israel or Egypt in MGM's new 65mm widescreen process. MGM, however, suspended production in early 1956.
 Links: a. Spain b. CinemaScope c. Stewart Granger d. CinemaScope
Example Output:
c