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: 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

Ex Output:
c


Ex Input:
Question: Which aircraft had a longer operational lifespan in the Royal Canadian Air Force between the McDonnell CF-101 Voodoo and the Avro CF-100 Canuck? 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. Avro Canada CF-100 Canuck b. Interceptor aircraft c. Interceptor aircraft d. Royal Canadian Air Force

Ex Output:
a


Ex Input:
Question: How many students attend the university that Lvov received a law degree from? Passage:Prince Lvov was born in Dresden, Germany, and descended from the sovereign Rurik dynasty princes of Yaroslavl. His family moved home to Popovka in the Aleksin district of Tula Governorate from Germany soon after his birth. He graduated from the University of Moscow with a degree in law, then worked in the civil service until 1893. During the Russo-Japanese War he organized relief work in the East and in 1905 joined the liberal Constitutional Democratic Party. A year later he won election to the First Duma, and was nominated for a ministerial position. He became chairman of the All-Russian Union of Zemstvos in 1914, and in 1915 he became a leader of the Union of Zemstvos as well as a member of Zemgor, a joint committee of the Union of Zemstvos and the Union of Towns that helped supply the military and tend to the wounded from World War I. In December 1916, after Prince Lvov's tirades at the Congress of Zemstvos, the Voluntary Organisations would allow no one to work for the government unless their collaboration were purchased by political concessions.
 Links: a. Dresden b. World War I c. Moscow State University d. Constitutional Democratic Party

Ex Output:

c