The value of the integral $\begin{align*}I = \int_0^1 x(1-x)^n dx \end{align*}$ is :

Question

( A ) $\frac{1}{n+1} + \frac{1}{n+2}$
( B ) $\frac{1}{n+1}$
( C ) $\frac{1}{n+1} - \frac{1}{n+2}$
( D ) $\frac{1}{n+2}$