The correct answer is (a) A=\(\begin{bmatrix}2&0&0\\0&2&0\\0&0&2\end{bmatrix}\)
The explanation: A matrix is called a scalar matrix if the elements along the diagonal of the matrix are equal and are non-zero i.e. aij=k for i=j and aij=0 for i≠j.
Therefore, the matrix A=\(\begin{bmatrix}2&0&0\\0&2&0\\0&0&2\end{bmatrix}\) is a scalar matrix.