Determine Whether Matrix B Is the Inverse of Matrix a by Finding

Determine whether matrix B is the inverse of matrix A by finding the product AB.
- $A = \left[ \begin{array} { r r } - 2 & 4 \\ 4 & - 4 \end{array} \right] , B = \left[ \begin{array} { l l } \frac { 1 } { 2 } & \frac { 1 } { 4 } \\ \frac { 1 } { 2 } & \frac { 1 } { 4 } \end{array} \right]$

A) $B \neq A ^ { - 1 }$
B) $\mathrm { B } = \mathrm { A } ^ { - 1 }$