Critical Reasoning (CR) | Re: You won’t be able to write well about the rock music of the 1960s

I had to choose between A&D. The only thing which made me to eliminate A - was Challenging his claim about her age (It's a premise not his claim) . His claim was "You won’t be able to write well about the rock music of the 1960s". Experts, I would appreciate your input to clarify btw. A and D.