The correct option is (a) A is a skew-symmetric matrix
To explain: Given that, A=\(\begin{bmatrix}1&0\\0&1\end{bmatrix}\)
∴A’=\(\begin{bmatrix}1&0\\0&1\end{bmatrix}\)
⇒-A’=\(\begin{bmatrix}-1&0\\0&-1\end{bmatrix}\)≠A. Hence, it is not a skew symmetric matrix.