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: When did the school Cerny got his M.B.A. open?
Passage:Keith Cerny is an American opera director and businessman. From 2004-2007 he was Executive Director and CFO of the San Francisco Opera and from 2010-2018 he was General Director of the Dallas Opera. In 2018 he was appointed General Director of the Calgary Opera. He is also the former CEO of Sheet Music Plus (2008-2010), the world's largest interest-based sheet-music company. He is a graduate of the University of California, Berkeley (B.A. in Music and B.S. in Physics), the Harvard Business School (M.B.A.), and the Open University in the United Kingdom (Ph.D. in Economic Development Studies/Econometrics). He also studied conducting, voice, and accompanying at the Guildhall School of Music and Drama in London and studied opera-accompanying in English National Opera's repetiteur training course. He also worked for McKinsey & Company for six years where he was a Senior Engagement Manager, and seven years with the consulting firm Accenture. He is also an Executive Board Member for Opera America.
Links: a. English National Opera b. Harvard Business School c. Guildhall School of Music and Drama d. Guildhall School of Music and Drama
Example Output: b

Example Input: Question: During what years was the Early Bronze Age? Passage:Iran is home to one of the world's oldest continuous major civilizations, with historical and urban settlements dating back to 7000 BC. The south-western and western part of the Iranian Plateau participated in the traditional Ancient Near East with Elam, from the Early Bronze Age, and later with various other peoples, such as the Kassites, Mannaeans, and Gutians. Georg Wilhelm Friedrich Hegel calls the Persians the "first Historical People". The Medes unified Iran as a nation and empire in 625 BC. The Achaemenid Empire (550330 BC), founded by Cyrus the Great, was the first true global superpower state and it ruled from the Balkans to North Africa and also Central Asia, spanning three continents, from their seat of power in Persis (Persepolis). It was the largest empire yet seen and the first world empire. The Achaemenid Empire was the only civilization in all of history to connect over 40% of the global population, accounting for approximately 49.4 million of the world's 112.4 million people in around 480 BC. They were succeeded by the Seleucid, Parthian, and Sasanian Empires, who successively governed Iran for almost 1,000 years and made Iran once again as a leading power in the world. Persia's arch-rival was the Roman Empire and its successor, the Byzantine Empire.
Links: a. Bronze Age b. Cyrus the Great c. Persepolis d. Central Asia
Example Output: a

Example Input: Question: Which of Moreno's partners was oldest? Passage:La Familia Michoacana, (English: The Michoacan Family) La Familia (English: The Family), or LFM is a Mexican drug cartel and a organized crime syndicate based in the Mexican state of Michoacan. Formerly allied to the Gulf Cartelas part of Los Zetasit split off in 2006. The cartel was founded by Carlos Rosales Mendoza a close associate of Osiel Cardenas. The second leader, Nazario Moreno Gonzalez, known as El Mas Loco (English: The Craziest One), preached his organization's divine right to eliminate enemies. He carried a "bible" of his own sayings and insisted that his army of traffickers and hitmen avoid using the narcotics they produce and sell. Nazario Moreno's partners were Jose de Jesus Mendez Vargas, Servando Gomez Martinez and Enrique Plancarte Solis, each of whom has a bounty of $2 million for his capture, and were contesting the control of the organization.
Links: a. Jose de Jesus Mendez Vargas b. Divinity c. Divinity d. Servando Gomez Martinez
Example Output:
a