Simplify the Radical Expression $$\sqrt [ 4 ] { 16 x ^ { 8 } }$$

Multiple Choice

Simplify the radical expression. Assume all variables represent nonnegative real numbers.
- $$\sqrt [ 4 ] { 16 x ^ { 8 } }$$

A) 2x2
B) 64
C) 4x2
D) $$- 2 x ^ { 2 }$$