Simplify Write the Answer Using Positive Exponents Only $\left( \frac { x ^ { - 9 } } { x ^ { - 3 } } \right) ^ { 3 }$

Multiple Choice

Simplify. Write the answer using positive exponents only.
- $\left( \frac { x ^ { - 9 } } { x ^ { - 3 } } \right) ^ { 3 }$

A) $x ^ { 18 }$
B) - $\begin{array} { r } 1 \\\times 18\end{array}$
C) $\frac { 1 } { \mathrm { x } ^ { 18 } }$
D) $- x ^ { 18 }$