Of the following three matrices, only two may be multiplied.

\[ A= \left[\begin{array}{ccc} 1 & -1 & -2 \\ 3 & -2 & -3 \\ -5 & 3 & 5 \\ 0 & 2 & 4 \end{array}\right] \hspace{1em} B= \left[\begin{array}{ccc} -1 & -5 & -2 \\ 1 & 4 & 2 \end{array}\right] \hspace{1em} C= \left[\begin{array}{cc} -3 & 4 \\ 0 & 1 \\ 3 & -1 \\ 4 & -6 \end{array}\right] \]

Explain which two can be multiplied and why. Then show how to find their product.