Find the Inverse of a If It Has One, or State

Multiple Choice

Find the inverse of A if it has one, or state that the inverse does not exist.
- $$A = \left[ \begin{array} { r r r } 6 & 0 & 0 \\0 & - 6 & 0 \\6 & 0 & 6\end{array} \right]$$

A)
$$\left[ \begin{array} { c c c } \frac { 1 } { 6 } & 0 & 0 \\0 & - \frac { 1 } { 6 } & 0 \\- \frac { 1 } { 6 } & 0 & \frac { 1 } { 6 }\end{array} \right]$$
B) Inverse does not exist
C)
$$\left[ \begin{array} { r r r } - 6 & 0 & 0 \\0 & 6 & 0 \\- 6 & 0 & - 6\end{array} \right]$$
D)
$$\left[ \begin{array} { c c c } - \frac { 1 } { 6 } & 0 & 0 \\0 & \frac { 1 } { 6 } & 0 \\\frac { 1 } { 6 } & 0 & - \frac { 1 } { 6 }\end{array} \right]$$