A derivative that vanishes

Trivia 1083

This theorem states that if $f$ is continuous on $[a,b]$, differentiable on $(a,b)$, and $f(a) = f(b)$, then there exists some $c \in (a,b)$ where $f'(c) = 0$. What is this theorem called?

AThe Mean Value Theorem BRolle's Theorem CThe Intermediate Value Theorem DFermat's Theorem on stationary points