Definition: In this task, you're given a question, along with a context passage which has extra information available on certain terms mentioned in it, i.e., the proper nouns in the passage. Your job is to determine whether information from more than one term is needed to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: What year was the School of American Ballet founded? Passage:Waring's training began in 1939 in San Francisco and Oakland at the age of 17. He was exposed to numerous kinds of dancing, including ballet at the San Francisco Ballet School with Harold Christensen and his brother, the Graham technique with Gertrude Schurr, and the interpretive dance of Raoul Pausé. Later, after serving in the Army in World War II, he studied in New York City at the School of American Ballet, and with Anna Halprin, Louis Horst, Antony Tudor, and Anatole Vilzak, and also took some classes with Merce Cunningham. Waring was very attracted to ballet and intrigued by its complex history and sensibility, and dance historian David Vaughan suggests that Waring's extensive knowledge of dance history played an important role in his work; Waring's dances became more balletic over time.


b