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 Lunen, 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 ("Wasserwirtschaftsverbande") 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 Kanale.
Links: a. Cologne-Minden trunk line b. Wasserverband Westdeutsche Kanale c. Datteln-Hamm Canal d. Weser
Example Output: c

Example Input: Question: Was Chevon Walker born in the Caribbeans? Passage:Chevon Walker (born May 9, 1987 in Montego Bay, Jamaica) is a former professional Canadian football running back and kick returner for the Winnipeg Blue Bombers of the Canadian Football League. He played NCAA football for the Sioux Falls Cougars. He played two years of his career as a professional football player in the Canadian Football League for the Hamilton Tiger-Cats. In 2014, the Ottawa Redblacks selected him in the expansion draft. He started the 2015 season with the Ottawa Redblacks before he was released on August 28, 2015. On September 1, 2015, it was announced that Walker had signed with the Winnipeg Blue Bombers. Chevon Walker has over 1000 rushing yards and seven touchdowns in three years of professional play.
Links: a. Hamilton Tiger-Cats b. Winnipeg Blue Bombers c. Canadian Football League d. Montego Bay
Example Output: d

Example Input: Question: How many fleets did Henry Osborn command during his career? Passage:By October 1757 Rowley had been given the task of commissioning the 60-gun fourth-rate . Once launched she joined Admiral Henry Osborn's fleet of 14 ships of the line in the Mediterranean. Osborn was at the time blockading the French under Admiral La Clue in the Spanish city of Cartagena preventing them from joining the fleet off Louisburg in Nova Scotia. French command had ordered the Marquis Duquesne to break through the British blockade and reinforce La Clue and then with superiority of numbers break out of Cartagena and make their way to America. Osborn intercepted Duquesne and his three ships of the line and one frigate. The subsequent action became known as the Battle of Cartagena and took place on 28 February 1758. Osborn's squadron captured two of the French line of battle ships and, under the guns of the Spanish castle the 60-gun French Oriflamme was driven on shore by the Montagu and the . Whilst the battle was not particularly grand the annihilation of the forces under Duquesne had two distinct effects. Firstly, the battle restored much of the pride that had been sapped from the navy after several defeats including those at Toulon and Minorca. Secondly, the siege of Louisburg and its surrender led to the French being marginalised as a significant power in North America. The battle can therefore be considered by the British as one of the defining achievements of the Seven Years' War. Had La Clue managed to break out from Osborn's close blockade the modern map of North America might appear quite different.
Links: a. Henry Osborn (Royal Navy officer) b. Henry Osborn (Royal Navy officer) c. Siege of Louisbourg (1758) d. Fourth-rate
Example Output:
a