Which is the best example of claim?

A: ...sometimes you have to follow your dreams, and that you should never give up just because someone says that you can't accomplish your goal.

B: When I was young, it seemed like everyone was always trying to tell me what I couldn't do.

C: "You won't understand those equations until you're older."

D: ...I've mastered those equations, played forward for two years, and am almost ready to play that piano piece.