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: How many days did the battle the Baron was killed in last? Passage:While they were travelling to Europe in 1914, the First World War broke out and the ship carrying Von Wolf and his wife was diverted to Rio de Janeiro. Jayta Humphreys had retained her American citizenship and found passage to Europe on a Dutch ship; legend has it the Baron had to travel disguised as a woman. On arrival in Europe the Baron rejoined the German army, and was killed at the Battle of the Somme in 1916, just two weeks after signing up. His wife could not bring herself to return to Namibia alone and never again laid claim to the majestic castle. She stayed on the coast of the Tegernmeer in Bavaria (since her stepfather had been appointed consul general in Munich), before settling in the late 1930s in Zurich, where she met and married Erich Schlemmer, the consul general of Siam. After the Von Wolfs left South Africa, their friend Max Count von Luttichau was given executorship of the farm, but it declared bankruptcy shortly after World War I, and since the South African government paid no compensation for this or several wartime raids, the house was sold for 7,500 to the Swedish Murrmann family. The new owner died shortly after his arrival and his son was killed in World War II, following which the castle was sold for 25,000 pounds to the private company Duwisib Pty Ltd and the rest of the land was divided and sold off. Jayta returned to the US to stay with her parents in Summit, New Jersey. Several changes in ownership later, the castle was acquired by the government in 1979 and extensively refurbished in 1991.
Links: a. Rio de Janeiro b. Europe c. Europe d. Battle of the Somme
Example Output: d

Example Input: Question: Which of the seas that the Sibiryakov sailed to was larger? Passage:A. Sibiryakov sailed on 28 June 1932 from the Krasny (previously Sobornoy) docks in Arkhangelsk, crossed the Kara Sea and chose a northern, unexplored way around Severnaya Zemlya to the Laptev Sea. In September, after calling at Tiksi and the mouth of the Kolyma, the propeller shaft broke and the icebreaker drifted for 11 days. However, A. Sibiryakov crossed the Chukchi Sea using improvised sails and arrived in the Bering Strait in October. A. Sibiryakov reached the Japanese port of Yokohama after 65 days, having covered more than in the Arctic seas. This was regarded as a heroic feat of Soviet polar seamen and Chief of Expedition Otto Schmidt and Captain Vladimir Voronin were received with many honors at their return to Russia.
Links: a. Arkhangelsk b. Tiksi c. Kara Sea d. Kolyma
Example Output: c

Example Input: Question: How old was Harry Doll the year the Supreme Court ruled to remove prayer from public schools? Passage:On July 10, 1961, Shehan returned to Baltimore as its Coadjutor Archbishop (with right of succession) and Titular Archbishop of Nicopolis ad Nestum. He succeeded Francis Patrick Keough as Archbishop of Baltimore on December 8 of that same year. In this position, he led the nation's first diocese and held precedence, except for Cardinals created earlier and without the honorary title of primacy, over the Church in America. After the Supreme Court ruled to remove prayer from public schools in 1962, Shehan warned that "secularization threatens to become a sort of state religion established by court decree". He was also a strong advocate of civil rights, banning segregation in all of Baltimore's Catholic institutions and walking in the March on Washington for Jobs and Freedom in 1963. He also maintained relations with Judaism and Eastern Orthodoxy. Cardinal Shehan worked with his friend Harry Lee Doll, Episcopal Bishop of Maryland and President of the Maryland Council of Churches on both civil rights and ecumenical issues. Along with the President of St. Mary's Seminary and University, Cardinal Shehan and Bishop Doll in 1968 founded Baltimore's Ecumenical Institute, in the city's Roland Park neighborhood.
Links: a. St. Mary's Seminary and University b. Judaism c. Catholic Church in the United States d. Harry Lee Doll
Example Output:
d