Choose the correct answer If f(x)=$\int\limits_0^x t\sin t\;dt,$ then f'(x) is

Question

$\begin{array}{1 1} (A) \;(cos x + x\; sin\; x) \\ (B)\; x \;\sin\; x \\ (C)\; x\; \cos x \\ (D)\; \sin x + x \cos x\end{array}$