Consider the following statements in respect of a skew-symmetric matrix $A$ of order $3$:

1. All diagonal elements are zero.

2. The sum of all the diagonal elements of the matrix is zero.

3. $A$ is orthogonal matrix.

Which of the statements given above are correct?

If $A=\left[\begin{array}{lll} 2 & 0 & 0 \\ 0 & 3 & 0 \\ 0 & 0 & 4 \end{array}\right]$, then which of the following statements are correct?

1. An will always be singular for any positive integer n.

2. An will always be a diagonal matrix for any positive integer n.

3. An will always be a symmetric matrix for any positive integer n.

Select the correct answer using the code given below: