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: Is the fraternity that Frank Kratovil joined still active? Passage:Frank Kratovil was born in Lanham, Maryland, spent his childhood in Prince George's County, Maryland. He is the son of Frank M. Kratovil Sr. and Lynnda Kratovil. Kratovil attended high school at Queen Anne School in Upper Marlboro and graduated in 1986. Kratovil received his bachelor's degree in 1990 from Western Maryland College. He joined Phi Delta Theta while there and played soccer, basketball and baseball. In soccer, he served as Captain for three years, was named to the Middle-Atlantic Conference All-Conference Team and received the Most Valuable Offensive Player Award and the Homer Earl Outstanding Player Award. Upon graduation, he was awarded the Bates Prize for the Most Outstanding Graduating Male, the Charles W. Havens Award, awarded to an intercollegiate athlete who "has shown by word and deeds the attributes of charity, altruism, benevolence, and a humane and compassionate concern for his fellow man", and the Carroll County Scholar-Athlete Award. Kratovil then graduated with honors from University of Baltimore School of Law in 1994. He served from 1994 to 1995 as Law Clerk for Judge Darlene G. Perry of Prince George's County Circuit Court. From 1995 to 1997 he served as Assistant State's Attorney for Prince George's County, Maryland.
Links: a. Lanham, Maryland b. Judge c. Lanham, Maryland d. Phi Delta Theta
Example Output: d

Example Input: Question: What year did Vaughn's producer form hiw own label after leaving Mercury? Passage:In 1971, Bob Shad, who had worked with her as producer at Mercury, asked her to record for his label, Mainstream, which he had founded after leaving Mercury. Breaking a four-year hiatus, Vaughan signed a contract with Mainstream and returned to the studio for A Time in My Life, a step away from jazz into pop music with songs by Bob Dylan, John Lennon, and Marvin Gaye arranged by Ernie Wilkins. She didn't complain about this eclectic change in direction, but she chose the material for her next album after admiring the work of Michel Legrand. He conducted an orchestra of over one hundred musicians for Sarah Vaughan with Michel Legrand, an album of compositions by Legrand with lyrics by Alan and Marilyn Bergman. The songs brought some of the musicians to tears during the sessions. But Shad wanted a hit, and the album yielded none. She sang a version of the pop hit "Rainy Days and Mondays" by the Carpenters for Feelin' Good. This was followed by Live in Japan, her first live album since 1963. Sarah Vaughan and the Jimmy Rowles Quintet (1974) was more experimental, containing free improvisation and some unconventional scatting.
Links: a. Mainstream Records b. John Lennon c. Feelin' Good (Sarah Vaughan album) d. Marvin Gaye
Example Output: a

Example Input: Question: In what year did the sketch that inspired the gravestone inscriptions in Plants vs. zombies first air on television? Passage:Plants vs. Zombies uses many cultural references in its names of stages and others. The gravestones' inscriptions ("Expired", "Ceased to Exist", "Just Resting", etc.) were taken from Monty Python's "Dead Parrot sketch". Three of the mini-games"Zombiquarium", "Beghouled" and "Beghouled Twist"take their names from two other PopCap games: Insaniquarium, Bejeweled and Bejeweled Twist respectively. Two levels in "vasebreaker" puzzles, "Scary Potter" and "Ace of Vase", take their names from Harry Potter and Ace of Base. Similarly, the "I, Zombie" (a reference to Isaac Asimov's "I, Robot") puzzles have levels called "Dead Zeppelin" (resembling Led Zeppelin) and "All your brainz r belong to us" (a play on the gaming meme "All your base are belong to us"). The name of the Torchwood plant is a reference to Doctor Who and its spin-off show Torchwood. Originally, the dancing zombie resembled Michael Jackson from the short film "Thriller". Though the Jackson-inspired zombie was present in the game before Jackson's death, the estate of Michael Jackson objected to its inclusion more than a year after his death; PopCap agreed to remove the Jackson-inspired zombie and replaced it with a more generic disco-dancing one for all future patches and releases of the game. A "disclaimer" in the game's almanac states "Any resemblance between Dancing Zombie and any persons living or dead is purely coincidental." Some Plants vs. Zombies advertisements parody controversial Evony ads, showing a drooling zombie instead of a voluptuous woman.
Links: a. Harry Potter b. Dead Parrot sketch c. All your base are belong to us d. All your base are belong to us
Example Output:
b