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: What was Sergei Ratnikov's previous employment before he was hired as JK Tallinna Kalev's manager? Passage:In January 2010, Sergei Ratnikov was appointed as manager. Tallinna Kalev won the 2011 Esiliiga were promoted back to the Meistriliiga. The club finished the 2012 season in ninth place, but avoided being relegated by defeating Tarvas 31 on aggregate in the relegation play-offs. In December 2012, Frank Bernhardt was appointed as manager. Tallinna Kalev finished the 2013 season in eighth place. In January 2014, former Estonia national team manager Tarmo Ruutli took over as manager. Ruutli subsequently left in March 2014 and Sergei Zamogilnoi took over as manager. Following a disappointing 2014 season, where Tallinna Kalev finished in 10th place and were relegated to the Esiliiga once again, Zamogilnoi was replaced by Marko Parnpuu. Tallinna Kalev returned to the Meistriliiga after finishing the 2017 season as runners-up. In November 2017, Parnupuu was replaced by Argo Arbeiter. The team finished the 2018 season in eighth place, after which Arbeiter left and Aleksandr Dmitrijev took over as manager.
Links: a. Tarmo Ruutli b. Argo Arbeiter c. Sergei Ratnikov d. Frank Bernhardt
Example Output: c

Example Input: Question: Who are the members of the group who collaborated with other singers multiple times for Bob Wills is Still the King? Passage:And in any case, people in Texas came to identify with the song. The work of the Austin-based group Asleep at the Wheel helped to keep popular knowledge of Wills going, and they collaborated with Clint Black on a new version of "Bob Wills Is Still the King" on a 1999 tribute album Ride With Bob. Another recording of the song by Asleep at the Wheel, this time in collaboration with Waylon's son Shooter Jennings together with Randy Rogers and Reckless Kelly, appeared on the 2015 effort . The song itself is collected on several Jennings live sets, compilations, and box sets, including RCA Country Legends (2001 compilation, includes studio version), Live from Austin, TX (recorded 1989, released 2006), and Nashville Rebel (2006 box set including studio version). Perhaps the most unexpected appearance was a performance by The Rolling Stones in Austin in 2006 during their A Bigger Bang Tour. Their arrangement featuring Ronnie Wood playing pedal steel guitar was captured on their 2007 The Biggest Bang concert DVD release.
Links: a. Reckless Kelly b. Asleep at the Wheel c. Asleep at the Wheel d. Randy Rogers Band
Example Output: b

Example Input: Question: Which structure of the final fortress is triangular in shape? Passage:On 7 October 1593, the superintendent of the Venetian Republic founded a revolutionary new kind of settlement: Palmanova. The city's founding date commemorated the victory of the Christian forces (supplied primarily by the Italian states and the Spanish kingdom) over the Ottoman Turks in the Battle of Lepanto in 1571, during the War of Cyprus. Also honored on 7 October was Saint Justina, chosen as the city's patron saint. Using all the latest military innovations of the 16th century, this small town was a fortress in the shape of a nine-pointed star, designed by Vincenzo Scamozzi. Between the points of the star, ramparts protruded so that the points could defend each other. A moat surrounded the town, and three large, guarded gates allowed entry. The construction of the first circle, with a total circumference of , took 30 years. Marcantonio Barbaro headed a group of Venetian noblemen in charge of building the town, Marcantonio Martinego was in charge of construction, and Giulio Savorgnan acted as an adviser. A second phase of construction took place between 1658 and 1690, and the outer line of fortifications was completed between 1806 and 1813 under the Napoleonic domination. The final fortress consists of: 9 ravelins, 9 bastions, 9 lunettes, and 18 cavaliers.
Links: a. Justina of Padua b. Lunette (fortification) c. Ravelin d. Battle of Lepanto
Example Output:
c