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: Where was the person whose guard Yermolov served in 1807 born? Passage:His own military genius blossomed during the Napoleonic Wars. During the 1805 Campaign, Yermolov served in the rear and advance guards and distinguished himself at Amstetten and Austerlitz. For his actions, he was promoted to colonel on 16 July 1806. The following year, he participated in the campaign in Poland, serving in Prince Bagration's advance guard. He distinguished himself commanding an artillery company in numerous rearguard actions during the retreat to Landsberg as well as in the Battle of Eylau. In June 1807, Yermolov commanded horse artillery company in the actions at Guttstadt, Deppen, Heilsberg and Friedland, being awarded the Order of St. George (3rd class, 7 September 1807). He was promoted to major general on 28 March 1808 and was appointed inspector of horse artillery companies. In early 1809, he inspected artillery companies of the Army of the Danube. Although his division took part in the 1809 campaign against Austria, Yermolov commanded the reserves in Volhynia and Podolsk gubernias, where he remained for the next two years. In 1811, he took command of the guard artillery company and in 1812, became the Chief of Staff of the 1st Western Army.
 Links: a. Volhynia b. Order of St. George c. Pyotr Bagration d. Battle of Friedland
Example Output: c

Example Input: Question: On what day did the season begin that Mark Sloan first appears? Passage:Mark first appears in season two, introduced as a highly respected otolaryngologist sub-specialized in plastic surgery and the childhood best friend of neurosurgeon Derek Shepherd (Patrick Dempsey). In his first appearance, he flirts with Meredith Grey, and Derek punches him in the face. Derek explains that Mark had an affair with his wife, Addison (Kate Walsh) while they were living in New York. Mark travels to Seattle, intent on convincing Addison to return with him to New York, but his offer is rejected and Derek declines to renew their friendship. Mark returns during season three at Addison's drunken behest, but she again rejects him once sober. Undeterred, Mark sells his successful private practice (which he previously shared with Derek) and takes over the plastics program at Seattle Grace Hospital. During Meredith's morphine rampage, Mark finds out about his nickname McSteamy which was given to him by her during his first trip to Seattle back when he attempted to get Addison back and earn Derek's friendship back. It is later revealed that Mark has at some point slept with all of Derek's sisters. Mark has a brief fling with Addison's friend, orthopedic surgeon Callie Torres (Sara Ramirez), and develops a friendship with Derek's girlfriend, intern Meredith Grey (Ellen Pompeo). It is revealed that after Derek left New York, Mark and Addison continued their relationship for two months, during which she conceived and aborted his child. Just weeks after moving to Seattle he quickly observes that Derek's true love was Meredith and tries to convince Addison that her marriage with Derek was over. Mark enters into a sixty-day abstinence pact with Addison, agreeing that if they can remain celibate for that time, Addison will give their relationship another chance. Addison ultimately breaks the pact by having sex with intern Alex Karev (Justin Chambers), and soon thereafter departs from Seattle to work in Los Angeles.
 Links: a. Grey's Anatomy (season 2) b. Grey's Anatomy (season 2) c. Kate Walsh (actress) d. Callie Torres
Example Output: a

Example Input: Question: Was the school where Constant Mews earned his bachelors and masters degrees established before 1950? Passage:Mews attended the University of Auckland and completed BA and MA degrees there in History. He carried out doctoral study at the University of Oxford, followed by five years (1980–1985) teaching British civilisation at the Universite de Paris III, while pursuing studies in medieval thought (focusing on Peter Abelard) in connection with Jean Jolivet, at the École pratique des hautes études en sciences religieuses. This was followed by two years as a Leverhulme research fellow at the University of Sheffield on editing the writings of Peter Abelard. Mews took up a position at Monash University as Lecturer in the Department of History in July 1987. He became involved in developing the Centre for Studies in Religion and Theology and in promoting studies in religion more generally, with a strong interest in interfaith work. He has had spells of study at the Institute for Advanced Study, Princeton, in 1990 and 2000, and has also again taught in Paris, at the École pratique des hautes études (Ve section) and in the École des hautes études en sciences sociales.
 Links: a. École pratique des hautes études b. École pratique des hautes études c. University of Auckland d. École pratique des hautes études
Example Output:
c