Solve the Problem $3 ^ { - x } = \frac { 1 } { 5 }$

Multiple Choice

Solve the problem.
-If $3 ^ { - x } = \frac { 1 } { 5 }$ , what does $9 ^ { x }$ equal?

A) $- 25$
B) 5
C) 25
D) $\frac { 1 } { 25 }$