Find the Indicated Sum or Difference, If It Is Defined $A = \left[ \begin{array} { r r } - 7 & 1 \\ 2 & 5 \end{array} \right]$

Find the indicated sum or difference, if it is defined.
-Compute the sum of $A = \left[ \begin{array} { r r } - 7 & 1 \\ 2 & 5 \end{array} \right]$ and $B = \left[ \begin{array} { l l } 6 & 2 \\ 6 & 3 \end{array} \right]$ .

A) $\left[ \begin{array} { r r } - 1 & 3 \\ 8 & 8 \end{array} \right]$
B) $[ 18 ]$
C) $\left[ \begin{array} { l l } 3 & 4 \\ 4 & 8 \end{array} \right]$
D) $\left[ \begin{array} { l l } - 1 & - 5 \\ - 1 & - 4 \end{array} \right]$