Solve the Equation $$3 ^ { - x } = \frac { 1 } { 9 }$$

Multiple Choice

Solve the equation.
- $$3 ^ { - x } = \frac { 1 } { 9 }$$

A) $\{ - 2 \}$
B) $\left\{ \frac { 1 } { 2 } \right\}$
C) $\left\{ \frac { 1 } { 3 } \right\}$
D) $\{ 2 \}$