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 many days did the battle the Baron was killed in last? Passage:While they were travelling to Europe in 1914, the First World War broke out and the ship carrying Von Wolf and his wife was diverted to Rio de Janeiro. Jayta Humphreys had retained her American citizenship and found passage to Europe on a Dutch ship; legend has it the Baron had to travel disguised as a woman. On arrival in Europe the Baron rejoined the German army, and was killed at the Battle of the Somme in 1916, just two weeks after signing up. His wife could not bring herself to return to Namibia alone and never again laid claim to the majestic castle. She stayed on the coast of the Tegernmeer in Bavaria (since her stepfather had been appointed consul general in Munich), before settling in the late 1930s in Zurich, where she met and married Erich Schlemmer, the consul general of Siam. After the Von Wolfs left South Africa, their friend Max Count von Lüttichau was given executorship of the farm, but it declared bankruptcy shortly after World War I, and since the South African government paid no compensation for this or several wartime raids, the house was sold for £7,500 to the Swedish Murrmann family. The new owner died shortly after his arrival and his son was killed in World War II, following which the castle was sold for 25,000 pounds to the private company Duwisib Pty Ltd and the rest of the land was divided and sold off. Jayta returned to the US to stay with her parents in Summit, New Jersey. Several changes in ownership later, the castle was acquired by the government in 1979 and extensively refurbished in 1991.
 Links: a. Rio de Janeiro b. Europe c. Europe d. Battle of the Somme
Example Output: d

Example Input: Question: What was the real name of the wrestler Buffalo defeated in order to win his first title in Osaka Pro? Passage:In April 1999, Yamada joined the Osaka Pro Wrestling promotion, where he began wrestling under a mask as Black Buffalo, a character inspired by the Osaka Kintetsu Buffaloes baseball team. He made his debut for the promotion at its first event on April 29, where he, Dick Togo and Violencia, forming the villainous alliance Legion of Violence (LOV), were defeated in a six-man tag team main event by Masato Yakushiji, Naohiro Hoshikawa and Super Delfin. Buffalo kept teaming with Togo for the rest of the year. On November 21, Buffalo won his first title in Osaka Pro, when he defeated Super Delfin for the UWF Super Welterweight Championship, only to lose it back to him seven days later. In early 2000, LOV was joined by Daio Quallt and Policeme~n, replacing Violencia. On May 1, Buffalo and Togo defeated Super Delfin and Super Demekin in the finals to win the 1st Anniversary Tag Tournament. In September, Buffalo took part in the inaugural Tenno-zan tournament, where he made it to the semifinals, before being eliminated by Super Delfin. After Dick Togo left Osaka Pro at the end of 2000, LOV was disbanded and replaced by the new group, FLUXxx, as a member of which Buffalo formed a new tag team named Infinity with Tsubasa. After reaching the semifinals of the 2001 Osaka Tag Festival, Buffalo and Tsubasa defeated Super Delfin and Takehiro Murahama on July 21 to win the vacant Osaka Pro Wrestling Tag Team Championship. They would lose the title to Murahama and Kaiju Zeta Mandora on August 24. The following October's Tenno-zan saw a repeat of the previous year's tournament as Buffalo was eliminated in the semifinals by Super Delfin. On January 27, 2002, Buffalo, Tsubasa and Gamma defeated Super Delfin, Super Demekin and Takehiro Murahama to win the Trios Cup Tournament. On August 25, Buffalo and Tsubasa regained the Osaka Pro Wrestling Tag Team Championship by defeating the Kishiwada Gurentai (Big Boss MA-G-MA and Daio Quallt). After a five-month reign, they would lose the title to Jyushin Thunder Liger and Takehiro Murahama on February 1, 2003.
 Links: a. Magnitude Kishiwada b. Super Delfin c. Super Delfin d. Super Delfin
Example Output: b

Example Input: Question: Who won the World Cup where the Costa Rican team had a prominent performance? Passage:Since the late 1980s, the team has continuously been visible as a solidly competitive side, with a prominent performance in the 1990 FIFA World Cup in Italy, making it to the knockout stage in their debut after finishing second in their group during the first phase, below Brazil. They also managed to qualify for the 2002 and 2006 FIFA World Cups. In 2014, Costa Rica made their best performance in history by finishing first in their group that consisted of three former World Cup champions: Uruguay, Italy, and England. During the Round of 16 they defeated Greece 5–3 via a penalty shootout after a 1–1 draw. Moreover, during the match against a much better team, Navas saved more than 15 shots due to the Costa Rican very weak defense. The match was characterized as "Navas vs Greece". They reached the quarterfinals for the very first time as the Ticos were defeated by the Netherlands also in a penalty shootout (3–4) after a scoreless draw on 5 July. Their 2018 World Cup campaign ended in a 4th place group stage exit with their only point coming from a 2-2 draw vs Switzerland.
 Links: a. 2006 FIFA World Cup b. 1990 FIFA World Cup c. 2006 FIFA World Cup d. Keylor Navas
Example Output:
b