Solve the Problem $\mathrm { A } = \left[ \begin{array} { r r r } 6 & - 1 & - 2 \\ - 4 & 7 & - 2 \end{array} \right]$

Multiple Choice

Solve the problem.
-Let $\mathrm { A } = \left[ \begin{array} { r r r } 6 & - 1 & - 2 \\ - 4 & 7 & - 2 \end{array} \right]$ and $\mathrm { B } = \left[ \begin{array} { r r r } 7 & 6 & 2 \\ - 7 & 7 & - 9 \\ - 4 & - 9 & 7 \end{array} \right]$ . Find $\mathrm { AB }$ .

A) $\left[ \begin{array} { r r r } 6 & - 1 & - 2 \\ - 4 & 7 & - 2 \\ 7 & 7 & - 2 \\ - 7 & 7 & - 9 \\ - 4 & - 4 & 7 \end{array} \right]$
B) $\left[ \begin{array} { r r r } 57 & 47 & 7 \\ - 69 & 43 & - 85 \end{array} \right]$
C) $\left[ \begin{array} { r r r } 42 & - 6 & - 4 \\ 28 & 49 & 18 \\ 16 & - 63 & - 14 \end{array} \right]$
D) $\left[ \begin{array} { r r } 57 & - 69 \\ 47 & 43 \\ 7 & - 85 \end{array} \right]$