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 long is the river that's located in western Sweetwater County? Passage:It rises in western Wyoming, in northern Sublette County, on the western side of the Continental Divide in the Bridger–Teton National Forest in the Wind River Range. It flows south through Sublette County and western Wyoming in an area known as the Upper Green River Valley, then southwest and is joined by the Big Sandy River in western Sweetwater County. At the town of La Barge, it flows into Fontenelle Reservoir, formed by Fontenelle Dam. Below there, it flows through open sage covered rolling prairie where it is crossed by the Oregon, California and Mormon emigration trails and then further south until it flows past the town of Green River and into the Flaming Gorge Reservoir in Southwestern Wyoming, formed by the Flaming Gorge Dam in northeastern Utah. Prior to the creation of the reservoir, the Blacks Fork joined the Green River south of Green River, today the mouth of Blacks Fork is submerged by the reservoir.
 Links: a. Big Sandy River (Wyoming) b. Flaming Gorge Reservoir c. Sweetwater County, Wyoming d. Mormon Trail
Example Output: a

Example Input: Question: What were the names of the parents of the musician Bolland particularly embraced? Passage:Growing up as "and only child in a house without culture," (Bolland says that his "mother and father had no use for art, literature or music"), he embraced the late 1960s pop culture explosion of "pirate radio stations, music (particularly Frank Zappa...), drug taking, psychedelia, "peace and love," "dropping out," the underground scene, Oz Magazine," and other aspects of hippy culture epitomised by underground comix such as Robert Crumb's Zap Comix. Having taken both O-Level and A-Level examinations in art, Bolland spent five years at art school (starting in 1969) learning graphic design and Art history. Learning to draw comics, however, was "more a self-taught thing," with Bolland eventually writing a 15,000-word dissertation in 1973 on Neal Adams – an "artist [his teachers] had never heard of." He would later recall:
 Links: a. Neal Adams b. Graphic design c. Zap Comix d. Frank Zappa
Example Output: d

Example Input: Question: Which person involved in the sale of the southern coast of Namibia is the oldest? Passage:German Namibians () are a community of people descended from ethnic German colonists who settled in present-day Namibia. In 1883, the German trader Adolf Lüderitz bought what would become the southern coast of Namibia from Josef Frederiks II, a chief of the local Oorlam people, and founded the city of Lüderitz. The German government, eager to gain overseas possessions, annexed the territory soon after, proclaiming it German South West Africa (). Small numbers of Germans subsequently immigrated there, many coming as soldiers (), traders, diamond miners, or colonial officials. In 1915, during the course of World War I, Germany lost its colonial possessions, including South West Africa (see History of Namibia); after the war, the former German colony was administered as a South African mandate. The German settlers were allowed to remain and, until independence in 1990, German remained an official language of the territory alongside Afrikaans and English.
 Links: a. World War I b. Adolf Lüderitz c. Josef Frederiks II d. Afrikaans
Example Output:
b