Simplify the Expression $$\sqrt [ 4 ] { ( x + 81 ) ^ { 4 } }$$

Multiple Choice

Simplify the expression. Include absolute value bars where necessary.
- $$\sqrt [ 4 ] { ( x + 81 ) ^ { 4 } }$$

A) $| x + 3 |$
B) $x + 3$
C) $x + 81$
D) $| x + 81 |$