Find the Cube Root $\sqrt [ 3 ] { 729 x ^ { 6 } }$

Multiple Choice

Find the cube root.
- $\sqrt [ 3 ] { 729 x ^ { 6 } }$

A) $9 x ^ { 2 }$
B) not a real number
C) $81 x ^ { 2 }$
D) $27 x ^ { 2 }$