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: Are there any penguins on any of the islands Otto visited? Passage:He led the 1901-1904 Swedish Antarctic Expedition, aboard the ship Antarctic. The expedition visited the Falkland Islands before the ship, commanded by seasoned Antarctic sailor Carl Anton Larsen, dropped Nordenskjöld's party off at Snow Hill Island, a small island off the coast of the Antarctic Peninsula. Nordenskiöld overwintered at Snow Hill Island, while Antarctic returned to the Falklands. The following summer Larsen brought her south, intending to retrieve the Nordenskiöld party, but she became trapped in ice which eventually crushed her hull, forcing Larsen and his crew to overwinter in a hastily constructed shelter on Paulet Island. Larsen and Nordenskjöld finally rendezvoused at their fall-back rescue hut at Hope Bay in late 1903, where they were picked up by the Argentine Navy corvette ARA Uruguay (commanded by Julián Irízar), which had been dispatched when Antarctic had failed to make her appointed return to South America the previous year. Despite its end and the great hardships endured, the expedition was considered a scientific success, with the parties having explored much of the eastern coast of Graham Land, including Cape Longing, James Ross Island, the Joinville Island group, and the Palmer Archipelago. The expedition, which also recovered valuable geological samples and samples of marine animals, earned Nordenskjöld lasting fame at home, but its huge cost left him greatly in debt.
 Links: a. Graham Land b. Palmer Archipelago c. Falkland Islands d. ARA Uruguay
Example Output: c

Example Input: Question: Who earned the bronze medal in the event where the Austrian athlete earned the gold? Passage:Sonja Henie of Norway won her third straight gold medal in the ladies' singles figure skating event, her last Olympic medal as she turned professional shortly after the Games. Karl Schäfer of Austria also successfully defended his men's singles figure skating title from Lake Placid. Sweden swept the medals in the cross-country 50 km, as did Norway in the Nordic combined. Norway's Ivar Ballangrud was the most successful athlete, winning three golds and a silver in speed skating and taking his career total to seven Olympic medals. Other multiple medal winners were Oddbjørn Hagen of Norway (one gold, two silvers), Ernst Baier of Germany (one gold, one silver), Joseph Beerli of Switzerland (one gold, one silver), Erik August Larsson of Sweden (one gold, one bronze), Birger Wasenius of Finland (two silvers, one bronze), Olaf Hoffsbakken of Norway (two silvers), Fritz Feierabend of Switzerland (two silvers) and Sverre Brodahl of Norway (one silver, one bronze).
 Links: a. Figure skating at the 1936 Winter Olympics – Men's singles b. Nordic combined at the 1936 Winter Olympics c. Fritz Feierabend d. Nordic combined at the 1936 Winter Olympics
Example Output: a

Example Input: Question: Were rearguard actions common in this period? Passage:On 19 May 1804, Ney received his Marshal's baton, emblematic of his status as a Marshal of the Empire, the Napoleonic era's equivalent of Marshal of France. In the 1805 campaign, Ney took command of VI Corps of the Grande Armée and was praised for his conduct at Elchingen. In November 1805, Ney invaded the Tyrol, capturing Innsbruck from Archduke John. In the 1806 campaign, Ney fought at Jena and then occupied Erfurt. Later in the campaign, Ney successfully besieged Magdeburg. In the 1807 campaign, Ney arrived with reinforcements in time to save Napoleon from defeat at Eylau, although the battle ended in a draw. Later in the campaign, Ney fought at Güttstadt and commanded the right wing at Friedland. On 6June 1808, Ney was created Duke of Elchingen. In August 1808, he was sent to Spain in command of VI Corps and won a number of minor actions. In 1809, he routed an Anglo-Portuguese force under Sir Robert Wilson at Baños. In 1810, Ney joined Marshal Masséna in the invasion of Portugal, where he took Ciudad Rodrigo from the Spanish and Almeida from the British and Portuguese, brusquely defeated a British force on the River Côa, and fought at Bussaco. During the retreat from Torres Vedras, Ney engaged Wellington's forces in a series of lauded rearguard actions (Pombal, Redinha, Casal Novo, Foz d'Arouce) through which he delayed the pursuing enemy forces long enough to allow the main French force to retreat unmolested. He was ultimately removed from his command for insubordination.
 Links: a. Battle of Puerto de Baños b. Rearguard c. Battle of Jena–Auerstedt d. Battle of Eylau
Example Output:
b