Matrix Algebra - General Aptitude - General Aptitude (GA) Previous Year Questions

Consider the following Assertion [a] and Reason [r]

[a] M is an orthogonal matrix, but not a skew-symmetric matrix.
\[ \mathbf{M} = \begin{bmatrix} 1 & 0 & 0 \\ 0 & \cos\theta & -\sin\theta \\ 0 & \sin\theta & \cos\theta \end{bmatrix} \]
[r] Because \(\mathbf{M}^T = \mathbf{M}^{-1}\) and \(\mathbf{M}^T \neq -\mathbf{M}\).

Determine the correctness or otherwise of the above Assertion [a] and Reason [r]