Write an Equivalent Expression in Exponential Form $$\log _ { 4 } x = - 3$$

Multiple Choice

Write an equivalent expression in exponential form.
- $$\log _ { 4 } x = - 3$$

A) $\{ - 12 \}$
B) $\{ 1 \}$
C) $\left\{ \frac { 1 } { 64 } \right\}$
D) $\left\{ \frac { 1 } { 81 } \right\}$