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: Is the CEO of Radioshack a female? Passage:Many store closings ensued at the mall in the early 1990s, including five chain clothing stores and a T.J. Cinnamons bakery all in late 1991 and early 1992. Despite these closures, the mall also gained Champs Sports and a dollar store, and its occupancy level of 92 percent was higher than the average occupancy rate of 85 percent for malls in the Midwestern United States at the time. Limited Brands (now L Brands) opened three stores then under its ownership in 1993: a combination Limited Express/Structure store (now known as Express and Express Men, respectively) and Victoria's Secret. The combined Limited Express/Structure took the place of Herman's World of Sporting Goods, which had closed earlier in the year. According to the mall's then-general manager, Limited Brands had wanted to open all three brands at the mall for several years, and that all three were highly demanded by shoppers due to their presence at Meridian Mall. Following these additions, Lansing and Meridian malls had nearly 60 stores in common with each other and nearly 40 others that were unique to each. In 1995, the mall received new planters and an enlarged customer service booth. Meanwhile, RadioShack and Regis Hairstylists moved to new storefronts, Lane Bryant expanded its existing store, and Buckle, Bombay Company, and Pacific Sunwear joined. These were followed in 1996 by Gymboree, Bath & Body Works, and the second Disney Store in the state of Michigan.
 Links: a. Regis Corporation b. Bombay Company c. RadioShack d. Regis Corporation
Example Output: c

Example Input: Question: How many casualties had the Japanese Army suffered by the time Vincent was sent to Tokyo? Passage:Born the son of Colonel Arthur Hare Vincent and Elizabeth Rose Manson and educated at Wellington College and the Royal Military Academy, Woolwich, Vincent was commissioned into the Royal Artillery as a second lieutenant on 24 July 1891. He was promoted to lieutenant on 24 July 1894 and to captain on 13 February 1900. He served with the China Expeditionary Force in late 1900 and then in the Second Boer War in South Africa. Following the end of the war, Vincent left Point Natal for India on the SS Ionian in October 1902 with other officers and men of the J Battery Royal Horse Artillery, and after arrival in Bombay, was stationed in Meerut, Bengal Presidency. In 1903, Vincent was sent to Tokyo to learn Japanese: he served as British military attaché with the Japanese Army during the Russo-Japanese War and, from 1 March 1904, was attached to the 2nd Division of the First Japanese Army in Manchuria.
 Links: a. Imperial Japanese Army b. Second lieutenant c. Second Boer War d. Royal Military Academy, Woolwich
Example Output: a

Example Input: Question: What aircraft beside the Sopwith Camel did No. 66 Squadron RFC operate? Passage:This extended training period meant that he had accumulated 138 flying hours in his pilot's logbook before he finally joined No. 66 Squadron RFC in Italy on 10 March 1918. He was assigned to "C" Flight, flying a Sopwith Camel single seat fighter, and became the preferred wingman of fellow Canadian ace Billy Barker. Birks' first aerial victory came on 18 March, when he destroyed a Rumpler reconnaissance aircraft over Pravisdomini, killing an Austro-Hungarian pilot named Shneeberger. Six days later, he set another reconnaissance aircraft on fire, killing the crew of Poelzi and Suski. His third victory would not come until 2 May, when he wounded Leutnant K. Kosiuski and drove him into a crash landing that destroyed his Albatros D.V. Two days later, Birks shot down and killed ace Oberleutnant Karl Patzelt, as well as F. Frisch. In addition to killing both Austro-Hungarian pilots, he destroyed both their Albatros D.Vs; they were credited as "captured" because they fell within Italian lines. The new ace shot down another D.V in flames a week later, on 11 May. He destroyed two Berg fighters in five minutes on a morning patrol on 19 May. The following day, he destroyed another. On 24 May, while flying with Barker, Birks was credited with shooting down Hungarian ace József Kiss of Flik 55J; Birks thus became a double ace. On 9 June Birks set another Albatros D.V on fire in mid-air. On the 21st, he capped his list of triumphs by destroying another D.V over Motta. Most unusually for a British pilot, he had no "soft" victories, such as "driven down out of control".
 Links: a. Pravisdomini b. Motta di Livenza c. Sopwith Camel d. No. 66 Squadron RAF
Example Output:
d