For the Function Given, Find $f ^ { \prime } ( x )$

Multiple Choice

For the function given, find $f ^ { \prime } ( x )$ $f ( x ) = x ^ { 3 } - 6 x - 9$

A) $x ^ { 2 } - 6$
B) $3 x ^ { 2 } - 9$
C) $3 x ^ { 2 } - 6$
D) $3 x ^ { 3 } - 6 x$
E) $x ^ { 3 } - 6 x - 9$