Definition: In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as `a` for Yes or `b` for No.
Input: Question: How old was Emmylou Harris when Tony Brown left her band? Passage:Following stints with the Dixie Melody Boys and Trav'lers Quartets, he joined J. D. Sumner and the Stamps Quartet in 1966. In 1972, he traveled briefly with the Blackwood Brothers, thereafter joining the Oak Ridge Boys as a member of The Mighty Oaks Band. Brown also played piano for Elvis Presley. He toured with the TCB Band for much of Presley's final two years and was a part of the 1976 "Jungle Room" recording sessions at Graceland. In 1979, he joined Emmylou Harris's backing band, the Hot Band, taking over for former Presley sideman Glen D. Hardin. Brown stayed with Harris until 1981. Later, he became a session musician in Nashville and toured with acts such as Rosanne Cash.


b