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 high is the gamma radiation from nuclear fuel? Passage:The nuclear fuel elements were made of refractory ceramic based on beryllium oxide, with enriched uranium dioxide as fuel and small amount of zirconium dioxide for structural stability. The fuel elements were hollow hexagonal tubes about long with distance between the outer parallel planes, with inside diameter of . They were manufactured by high-pressure extruding of the green compact, then sintering almost to its theoretical density. The core consisted of 465,000 individual elements stacked to form 27,000 airflow channels; the design with small unattached elements reduced problems related with thermal stresses. The elements were designed for average operation temperature of ; the autoignition temperature of the reactor base plates was only 150 °C higher. The neutron flux was calculated to be 9×10 neutrons/(cm·s) in the aft and 7×10 neutrons/(cm·s) in the nose. The gamma radiation level was fairly high due to the lack of shielding; radiation hardening for the guidance electronics had to be designed.
 Links: a. Beryllium oxide b. Radiation hardening c. Nuclear fuel d. Radiation hardening
Example Output: c

Example Input: Question: Which league were the second team Farrell played for in? Passage:John A. "Jack" Farrell (July 5, 1857 – February 9, 1914), also known as "Moose", was an American Major League Baseball player who played mainly second base in his 11 seasons. Born in Newark, New Jersey, Farrell made his major league debut for the Syracuse Stars of the National League, where he played the majority of that season, until moving onto the Providence Grays, where he played the next six seasons. His career numbers include 877 hits in 884 games played, 23 home runs, and a .243 batting average. In , he began the season as the player-manager for the Grays, compiling a 24 win, 27 loss record. On August 3, Farrell quit as "captain" of the team. He was succeeded by outfielder Tom York, and the team finished the season with 23 wins against 10 losses, good for second place.
 Links: a. Games played b. Tom York (baseball) c. Providence Grays d. Major League Baseball
Example Output: c

Example Input: Question: How many members did the Kach movement have the year Dayan joined them? Passage:Yosef Dayan emigrated to Israel in 1968, and became a member of the right-wing Kach movement. Dayan is the founder of "Malchut Israel", a right-wing religious-political group in Israel advocating a return of the monarchy. In 2004, he became a member of the newly reconstituted Sanhedrin, a duplicate of the religious tribunal which convened during the time of the Second Temple, a group that had traditionally had seventy-one members. He has also achieved certain notoriety for his alleged central participation in so-called "death curse" ceremonies or Pulsa diNura aimed at Yitzhak Rabin and Ariel Sharon. These curses were presumably to request divine retribution after those former Prime Ministers advocated Israeli withdrawal from certain areas considered by some as inalienable parts of the promised land. Incidentally, Yitzhak Rabin was murdered soon after the first curse, and Ariel Sharon left in a persistent vegetative state after a brain haemorrhage following the second. He is also known to have supported Baruch Goldstein's (a fellow Meir Kahane disciple) terrorist actions in the Cave of the Patriarch's Massacre.
 Links: a. Kach and Kahane Chai b. Promised Land c. Baruch Goldstein d. Ariel Sharon
Example Output:
a