Instructions: 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.
Input: Question: Has Alice in Chain's singer joined more than one band? Passage:Audioslave's history dates back to October 18, 2000, when Rage Against the Machine's lead vocalist Zack de la Rocha announced he was leaving the band, citing a breakdown in its "decision-making process". This led to the breakup of Rage Against the Machine, but the remaining three members of the bandTim Commerford, Tom Morello, and Brad Wilkdecided to stay together and announced plans to continue with a new vocalist. Several vocalists jammed with the three, including B-Real of Cypress Hill, but they did not want another rapper or anybody who sounded like de la Rocha. Contrary to popular belief, Layne Staley of Alice in Chains neither auditioned nor was asked to join the new project. Tom Morello denied this claim on his Twitter account in 2015. Music producer and friend Rick Rubin suggested that they play with Chris Cornell of Soundgarden. Rubin also persuaded the three of them to go into group therapy with performance coach Phil Towle after the breakup. Rubin was confident that with the right new voice, Rage Against the Machine had the potential to become a better band; he believed "it could turn into a Yardbirds-into-Led Zeppelin scenario." Commerford later credited Rubin for being the catalyst that brought Audioslave together. He called him "the angel at the crossroads" because "if it wasn't for him, I wouldn't be here today."
Links: a. Brad Wilk b. Layne Staley c. Zack de la Rocha d. Led Zeppelin
Output:
b