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: In what year was CIA pilot Francis Gary Powers born? Passage:Strategic Air Command was formed by the United States Air Force after World War II to provide an active defense against any surprise attack by the Soviet Union. Though it had been an ally against Germany and Japan during World War II, by 1948 the Soviet Union showed a propensity to instigate problems with Britain, France and the United States. In August 1949, the Soviet Union detonated its first nuclear weapon and by the early 1950s had detonated a hydrogen bomb. The war of words between the two superpowers escalated during 1950s and 1960s into a nuclear arms race. By 1970 the United States was using a "Triad Defense System" composed of nuclear submarines armed with nuclear missiles, land based intercontinental ballistic missiles with nuclear warheads and bombers capable of delivering hydrogen bombs on enemy targets. The Boeing B-52 Stratofortress bomber had been designed in the early 1950s by Boeing Aircraft Company to give the United States Air Force the capability of delivering nuclear weapons far inside the territory of Soviet Russia. The planes were to fly at high altitude with enough fuel to hit their target. In May 1960, the Soviet Union made known its capability to shoot such high altitude planes out of the sky by using a surface to air missile to strike CIA pilot Francis Gary Powers' U-2 spy plane over Russian territory. From that point on, the high-altitude B-52 had to be modified to conduct missions at low level, something it was not intended to be.
 Links: a. Strategic Air Command b. Intercontinental ballistic missile c. Intercontinental ballistic missile d. Francis Gary Powers
Example Output: d

Example Input: Question: What band(s) the artist whose song "Chamakay" Polachek contributed vocals belong to? Passage:In 2010, she joined Jorge Elbrecht of Brooklyn-based Violens to record a "sgin" of Justin Bieber's "Never Let You Go": "We went on YouTube to find a video among the highest ranks of hits, and came across 'Never Let You Go'. We went on to make what we call a 'sgin' (anagram of the word 'sing')—an original song written specifically to synch into someone else's video on mute". Caroline shot and directed video for Violens' "It Couldn't Be Perceived". Polachek and Elbrecht collaborated again in 2014 on two singles, "I.V. Aided Dreams (feat. Caroline Polachek)" and "Full Mental Erase (feat. Caroline Polachek)". In 2012, she sang with Ice Choir (solo project of Kurt Feldman of The Pains of Being Pure at Heart) on the song "Everything Is Spoilt by Use" and directed/edited its official video. Caroline contributed vocals to Blood Orange's "Chamakay" (2013), collaborating with Blood Orange again on "Holy Will" (2018). In late 2013, Polachek wrote and produced "No Angel", which was featured on Beyoncé's critically acclaimed fifth studio album, Beyoncé. Thanks to this song, at the 57th Annual Grammy Awards, she received a Grammy Award nomination for Album of the Year. Polachek then collaborated with PC Music's, Danny L Harle in early 2016 on the single "Ashes of Love". Polachek collaborated with felicita throughout his album "Hej!" (PC Music 2018) including an arrangement of the Polish traditional song "Byl Sobie Krol" (released under the title "Marzipan"), and with Charli XCX on Pop 2 (2017) on tracks "Tears (feat. Caroline Polachek)" and "Delicious (feat. Tommy Cash).
 Links: a. Danny L Harle b. Dev Hynes c. Beyoncé (album) d. Charli XCX
Example Output: b

Example Input: Question: Which of the universities that Gunther attended or earned awards from was oldest? Passage:In 1919, after the end of the war, he started his writing career. He wrote a polemical work entitled "The Knight, death and the devil: the heroic idea", a reworking of the tradition of German Pagan-Nationalist Romanticism into a form of "biological nationalism". Heinrich Himmler was very impressed by this book. In 1922 Günther studied at the University of Vienna while working in a museum in Dresden. In 1923 he moved to Scandinavia to live with his second wife, who was Norwegian. He received scientific awards from the University of Uppsala and the Swedish Institute for Race Biology, headed by Herman Lundborg. In Norway he met Vidkun Quisling. In May 1930 he was appointed to the University of Jena by Wilhelm Frick who had become the first NSDAP minister in a state government when he was appointed minister of education in the right-wing coalition government formed in Thuringen following an election in December 1929. In 1935 he became a professor at the University of Berlin, teaching race science, human biology and rural ethnography. From 1940 to 1945 he was professor at Albert Ludwigs University.
 Links: a. University of Vienna b. Wilhelm Frick c. Dresden d. Nazi Party
Example Output:
a