The matrix $\begin{bmatrix}1 & 0 & 0\\0 & 2 & 0\\0 & 0 & 4\end{bmatrix}$ is a

Question

$$\begin{array}{1 1}(A)\quad identity\;matrix & (B)\quad symmetric\;matrix\\(C)\quad skew\;symmetric\;matrix & (D)\quad none\;of\;these.\end{array}$$