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 was the man whose name is used as the unit of radio wave frequency born? Passage:A modulated radio wave, carrying an information signal, occupies a range of frequencies. See diagram. The information (modulation) in a radio signal is usually concentrated in narrow frequency bands called sidebands (SB) just above and below the carrier frequency. The width in hertz of the frequency range that the radio signal occupies, the highest frequency minus the lowest frequency, is called its bandwidth (BW). A given amount of bandwidth can carry the same amount of information (data rate in bits per second) regardless of where in the radio frequency spectrum it is located, so bandwidth is a measure of information-carrying capacity. The bandwidth required by a radio transmission depends on the data rate of the information (modulation signal) being sent, and the spectral efficiency of the modulation method used; how much data it can transmit in each kilohertz of bandwidth. Different types of information signals carried by radio have different data rates. For example, a television (video) signal has a greater data rate than an audio signal.
Links: a. Data signaling rate b. Carrier wave c. Hertz d. Audio signal
Example Output: c

Example Input: Question: Which comedy series for which Levitan was nominated for a 1996 Emmy ran longer? Passage:As executive producer, Levitan won an Emmy Award in 1996 for Frasier in the Outstanding Comedy Series category. He was also nominated in that same year for Outstanding Writing in Comedy Series category for The Larry Sanders Show. He was nominated for an Emmy in the Outstanding Writing for a Comedy Series category for Just Shoot Me! and two more as executive producer. Levitan won the Humanitas Prize (for writers whose work best communicates and encourages human values) in 1996 for the Frasier episode titled "Breaking the Ice". Levitan has also won a CableACE Award and a Writers Guild nomination for The Larry Sanders Show. He also garnered a Producers Guild Award and a Television Critics Association Award for Frasier, a People's Choice Award for Stark Raving Mad and a Golden Globe nomination for Just Shoot Me!
Links: a. Just Shoot Me! b. Frasier c. Frasier d. CableACE Award
Example Output: b

Example Input: Question: What year was the company founded where Silvestri work at in London, England? Passage:Gary di Silvestri is a graduate of Monsignor Farrell High School in Staten Island, New York, where he was a member of the football, wrestling and track & field teams. He graduated salutatorian and was awarded the top student athlete on Staten island. He has an undergraduate degree from Georgetown University where he graduated Magna Cum Laude and was inducted into the Phi Beta Kappa National Honor Society. Gary also has a Masters of Business Administration from Columbia University, where he graduated with honors and was inducted into the Beta Gamma Sigma national honors society. He has had a long career in financial services, having worked for Credit Suisse First Boston in London, England; and Morgan Stanley in both London and New York City. In 1997, di Silvestri founded Deutsche Suisse Asset Management, and he said his business success had allowed him to pursue philanthropy full time.
Links: a. Credit Suisse First Boston b. Morgan Stanley c. Master of Business Administration d. Beta Gamma Sigma
Example Output:
a