Explanation
Correct answer: C.
Choice C is the best answer. The sentence uses the quotation from Henderson to support a claim about Tharpe’s contribution to rock ’n’ roll, noting that the impact Tharpe had on the genre led Henderson to call her "the unquestioned founding mother of rock ’n’ roll."
Why the other choices are wrong
Choice A
Choice A is incorrect. While the sentence makes the claim that Tharpe had a major impact on rock ’n’ roll, it doesn’t use a quotation to support this claim.
Choice B
Choice B is incorrect. The sentence presents Henderson’s opinion that Tharpe had a major impact on rock ’n’ roll, but it doesn’t use a quotation to support this claim.
Choice D
Choice D is incorrect. While the sentence includes a quotation about audience reactions to Tharpe’s music, the sentence describes Tharpe as a gospel musician; it doesn’t support a claim about her contribution to rock ’n’ roll.