Let \( A = \begin{bmatrix} 0 & -2 \cr 2 & 0 \end{bmatrix} \). If \( M \) and \( N \) are two matrices given by \( M =\displaystyle \sum_{k=1}^{10} A^{2k} \) and \( N = \displaystyle \sum_{k=1}^{10} A^{2k-1} \) then \( MN^{2} \) is:
A non-identity symmetric matrix
A skew − symmetric matrix
Neither symmetric nor skew-symmetric matrix
An identity matrix