Solve the Equation and Express the Solution in Exact Form $$\log _ { 4 } \left( \log _ { 4 } x \right) = 1$$

Multiple Choice

Solve the equation and express the solution in exact form.
- $$\log _ { 4 } \left( \log _ { 4 } x \right) = 1$$

A) {16}
B) {4}
C) {256}
D) {8}