Question

Let $g$ be a twice-differentiable, increasing function of $t$. If $g(0)=20$ and $g(10)=220$, which of the following must be true on the interval $0\ \textless \ t\ \textless \ 10$ ?
(A) $g^{\prime}(t)=0$ for some $t$ in the interval.
(B) $g^{\prime}(t)=20$ for some $t$ in the interval.
(C) $g^{\prime \prime}(t)=0$ forseme $t$ in the interval.
(D) $g^{\prime \prime}(t)\ \textgreater \ 0$ for all $t$ in the interval.