Simplify the Radical $\sqrt [ 3 ] { 108 }$ A) $3 \sqrt [ 3 ] { 4 }$

Simplify the radical. Assume that all variables represent positive numbers.
- $\sqrt [ 3 ] { 108 }$

A) $3 \sqrt [ 3 ] { 4 }$
B) 12
C) 3
D) $3 \sqrt [ 3 ] { 12 }$