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: For how many years did the man serve as President that swept all five boroughs of NYC in 1964? Passage:Roosevelt won his home state by means of a dominance of the massively populated New York City area, performing even more strongly than he had in 1932. Roosevelt took over seventy percent of the vote in the boroughs of Manhattan, Brooklyn, and the Bronx, and took over sixty percent of the vote in Queens and Staten Island. For the era, this was an historically overwhelming victory for a Democratic presidential candidate in the five boroughs of New York City, and enough to easily secure a statewide win for Roosevelt. The emergence of the New Deal Coalition was at its peak in 1936, and made American cities with their powerful political machines core bases of support for the Democratic Party. The Great Depression had accelerated the process of urbanization of the Democratic Party which had begun with the election of 1928. Roosevelt’s landslide win in New York City was a fruit born by this process, and over the whole nation he achieved majorities in the largest cities totalling twice what Harding had achieved in 1920. 1936 was the third election in a row in which Democrats had won all five boroughs of NYC, following 1928 and 1932. After 1936, New York City would remain Democratic overall in every election that has followed, although no presidential candidate would sweep all five boroughs of NYC again until Lyndon Johnson in 1964. Partly as a consequence of this, FDR’s 1936 victory in New York State would also be the strongest statewide Democratic performance ever in terms of both margin and vote share until 1964.
 Links: a. Lyndon B. Johnson b. 1964 United States presidential election in New York c. Manhattan d. 1928 United States presidential election
Example Output: a

Example Input: Question: Which group ruled the area for a longer period of time, the Arabs or the Byzantines? Passage:The first permanent Arab settlement on Sicily occurred in 827, but it was not until Taormina fell in 902 that the entire island fell under their sway, though Rometta held out until 965. In that year the Kalbids established the independence of their emirate from the Fatimid Caliphate. In 1061 the first Norman liberators took Messina, and by 1071 Palermo and its citadel (1072) were captured. In 1091 Noto fell to the Normans, and the conquest was complete. Malta fell later that year, though the Arab administration was kept in place, marking the final chapter of this period. The conquests of the Normans established Roman Catholicism firmly in the region, where Eastern Christianity had been prominent during the time of Byzantine rule and even remained significant during Islamic period. Widespread conversion ensued, leading to the disappearance of Islam in Sicily by the 1280s. In 1245, Muslim Sicilians were deported to the settlement of Lucera, by order of Holy Roman Emperor Frederick II. In 1300, Giovanni Pipino da Barletta, count of Altamura, seized Lucera and exiled or sold into slavery its population, bringing an end to the medieval Muslim presence in Italy.
 Links: a. Messina b. Taormina c. Frederick II, Holy Roman Emperor d. Frederick II, Holy Roman Emperor
Example Output: b

Example Input: Question: When was the university founded that granted Morrey a PHD? Passage:Morrey graduated from Ohio State University with a B.A. in 1927 and a M.A. in 1928, and then studied at Harvard University under the supervision of George Birkhoff, obtaining a Ph.D. in 1931 with a thesis entitled Invariant functions of Conservative Surface Transformations. After being awarded his Ph.D, he was a National Research Council Fellow at Princeton, at the Rice Institute and finally at the University of Chicago. He became a professor of mathematics at UC Berkeley in 1933, hired by Griffith Conrad Evans, and was a faculty member until his retirement in 1973. In Berkeley, he was early given several administrative duties, for example being the Chairman of the Department of Mathematics during the period 1949–1954, and being the Acting Chairman, the Vice Chairman and the Director of the Institute of Pure and Applied Mathematics at various times. During the years 1937–1938 and 1954–1955 he was a member of the Institute for Advanced Studies: he was also Visiting Assistant Professor at Northwestern University, Visiting Professor at the University of Chicago and Miller Research Professor at Berkeley. During World War II he was employed as a mathematician at the U.S. Ballistic Research Laboratory in Maryland.
 Links: a. Harvard University b. Doctor of Philosophy c. Northwestern University d. Harvard University
Example Output:
a