Simplify the Expression $\sqrt { 4 x ^ { 8 } }$

Multiple Choice

Simplify the expression.
- $\sqrt { 4 x ^ { 8 } }$

A) $2 x ^ { 8 }$
B) $4 x ^ { 4 }$
C) $| 2 x |$
D) $2 x ^ { 4 }$