Perform the Indicated Operations $\sqrt { 12 x ^ { 3 } } - 8 \sqrt { 108 x ^ { 3 } }$

Multiple Choice

Perform the indicated operations. Assume that all variables represent positive numbers.
- $\sqrt { 12 x ^ { 3 } } - 8 \sqrt { 108 x ^ { 3 } }$

A) $- 8 \sqrt { - 96 x ^ { 3 } }$
B) $- 46 x \sqrt { 3 x }$
C) $50 x \sqrt { 3 x }$
D) $- 46 \sqrt { 3 x ^ { 3 } }$