Find the Matrix Product When Possible $A = \left[ \begin{array} { r r } 1 & - 2 \\ 4 & 3 \end{array} \right]$

Multiple Choice

Find the matrix product when possible.
-Given $A = \left[ \begin{array} { r r } 1 & - 2 \\ 4 & 3 \end{array} \right]$ and $B = \left[ \begin{array} { r r } 0 & - 1 \\ 5 & 4 \end{array} \right]$ , find $A B$ and $B A$ .

A)
$\mathrm { AB } = \left[ \begin{array} { r r } - 4 & - 3 \\ 21 & 2 \end{array} \right] ; \mathrm { BA } = \left[ \begin{array} { r r } - 10 & - 9 \\ 15 & 8 \end{array} \right]$
B)
$\mathrm { AB } = \left[ \begin{array} { r r } 0 & 2 \\ 20 & 12 \end{array} \right] ; \mathrm { BA } = \left[ \begin{array} { r r } 0 & 2 \\ 20 & 12 \end{array} \right]$
C)
$\mathrm { AB } = \left[ \begin{array} { r r } 10 & 7 \\ - 15 & - 16 \end{array} \right] ; \mathrm { BA } = \left[ \begin{array} { r r } 4 & 3 \\ - 11 & - 22 \end{array} \right]$
D)
$\mathrm { AB } = \left[ \begin{array} { r r } - 10 & - 9 \\ 15 & 8 \end{array} \right] ; \mathrm { BA } = \left[ \begin{array} { r r } - 4 & - 3 \\ 21 & 2 \end{array} \right]$