Use the Derivative Of $f ( x ) = 2 x ^ { 3 } + 3 x ^ { 2 }$

Multiple Choice

Use the derivative of $f ( x ) = 2 x ^ { 3 } + 3 x ^ { 2 }$ to determine any points on the graph of $f ( x )$ at which the tangent line is horizontal.

A) $( 1,5 )$ and $( - 1,1 )$
B) $( - 1 , - 8 )$
C) $( 0,0 )$ and $( - 1,1 )$
D) $( 2,0 )$
E) $f ( x )$ has no points with a horizontal tangent line.