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

(A) Null matrix
(B) Unit matrix
(C) Symmetric matrix
(D) Skew-symmetric matrix

Choose the correct answer from the options given below:

(A), (C) and (D) only

The correct answer is Option (3) → (A), (C) and (D) only

The given matrix has all elements equal to $0$.

So it is a null matrix.

Also, its transpose is itself, so it is symmetric.

And since $A^{T}=-A$ also holds for the zero matrix, it is skew-symmetric as well.

It is not a unit matrix.

final answer: $\text{(A), (C) and (D)}$