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 people did Arnstadt command as a company commander of the 6th border company in Dermbach? Passage:In June 1949, Arnstadt registered for service with the Volkspolizei, the police force of the Soviet Occupation Zone, becoming an Anwarter der VP (police cadet) with the Kasernierte Volkspolizei in Gotha. In March 1950, Arnstadt was appointed to the German Border Police (Deutsche Grenzpolizei) in Dermbach, patrolling the Inner German border with West Germany. In 1952, Arnstadt failed his first attempt to become an officer at the police school in Sondershausen. In 1953, his marriage ended in divorce, with his two children Veronika and Uwe staying with the mother, and remarried shortly after. In 1954, Arnstadt passed his officer training at Sondershausen and was appointed the rank of Unterleutnant, and the following year was promoted to lieutenant. Arnstadt functioned as a recruiter for the German Border Police until 1957 when he was appointed as a company commander of the 6th border company in Dermbach. Arnstadt was responsible for a section of the border at Wiesenfeld, a region of Bezirk Suhl in the Rhon Mountains at the westernmost point of the Warsaw Pact. Arnstadt's section contained the highly-strategic Fulda Gap, which aroused the special interest of NATO, and a short distance from the US Army's Observation Post Alpha. Arnstadt moved with his wife to Wiesenfeld and in April 1957 became an unofficial collaborator (Geheimer Informator) of the Ministry for State Security (Stasi) until this relationship was ended fourteen months later.
Links: a. Company commander b. Inner German border c. Dermbach d. Kasernierte Volkspolizei
Example Output: a

Example Input: Question: Did other scientists keep blending inheritance open for further consideration? Passage:In the preface, Fisher considers some general points, including that there must be an understanding of natural selection distinct from that of evolution, and that the then-recent advances in the field of genetics (see history of genetics) now allowed this. In the first chapter, Fisher considers the nature of inheritance, rejecting blending inheritance, because it would eliminate genetic variance, in favour of particulate inheritance. The second chapter introduces Fisher's fundamental theorem of natural selection. The third considers the evolution of dominance, which Fisher believed was strongly influenced by modifiers. Other chapters discuss parental investment, Fisher's geometric model, concerning how spontaneous mutations affect biological fitness, Fisher's principle which explains why the sex ratio between males and females is almost always 1:1, reproductive value, examining the demography of having girl children. Using his knowledge of statistics, the Fisherian runaway, which explores how sexual selection can lead to a positive feedback runaway loop, producing features such as the peacock's plumage. He also wrote about the evolution of dominance, which explores genetic dominance. The last five chapters (8-12) include Fisher's more idiosyncratic views on eugenics.
Links: a. Sexual selection b. Demography c. Blending inheritance d. Parental investment
Example Output: c

Example Input: Question: What grades attend the school near Boat Club Road? Passage:FM 1220 begins at an intersection with SH 183 in the Far Greater Northside area of Fort Worth. The highway travels in a northwestern direction along Azle Avenue through a residential area and runs along the northern edge of Sansom Park before entering Lake Worth. In Lake Worth, FM 1220 has a junction with I-820 and turns north onto Boat Club Road near Lake Worth High School. The highway travels in a northern direction near several subdivisions, running between Lake Worth and Marine Creek Reservoir, before re-entering Fort Worth near Saginaw. FM 1220 continues to run near several subdivisions in far northwest Fort Worth and turns west north of an intersection with Park Drive, then enters the town of Eagle Mountain. The highway runs through the town and runs close to Eagle Mountain Lake. West of Eagle Mountain, the Boat Club Road designation leaves the highway, with FM 1220's local designation becoming Morris Dido Newark Road. The highway runs in a northwestern direction near the eastern shore of Eagle Mountain Lake with state maintenance ending at Peden Road at the southern boundary of Pecan Acres; Morris Dido Newark Road continues past Peden Road for another to FM 718 near Newark.
Links: a. Lake Worth High School (Texas) b. List of Farm to Market Roads in Texas (700799) c. Eagle Mountain Lake d. Lake Worth High School (Texas)
Example Output:
a