The inverse of the matrix $\begin{bmatrix} 2 & 1 \\ 1 & 3 \end{bmatrix}$ is :

Question

( A ) $ \frac{2}{5}\begin{bmatrix} -3 & 1 \\ 1 & 2 \end{bmatrix}$
( B ) $ \frac{1}{5}\begin{bmatrix} 3 & -1 \\ -1 & 2 \end{bmatrix}$
( C ) $ \frac{1}{5}\begin{bmatrix} -3 & 1 \\ 1 & 2 \end{bmatrix}$
( D ) $ \frac{1}{5}\begin{bmatrix} 2 & 1 \\ 1 & 3 \end{bmatrix}$