For the Given Functions F and G, Find the Composition $$f ( x ) = x ^ { 3 } + 6 x ; g ( x ) = - 3 x$$

Multiple Choice

For the given functions f and g, find the composition.
- $$f ( x ) = x ^ { 3 } + 6 x ; g ( x ) = - 3 x$$
Find $( f \circ g ) ( x )$ .

A) $- 27 x ^ { 3 } - 18 x$
B) $- 27 x ^ { 2 } - 18 x$
C) $- 3 x ^ { 3 } + 6 x$
D) $- 3 x ^ { 3 } - 18 x$