Use the Derivative Of $f ( x ) = 3 x ^ { 4 } + 4 x ^ { 3 }$

Multiple Choice

Use the derivative of $f ( x ) = 3 x ^ { 4 } + 4 x ^ { 3 }$ to determine any points on the graph of $f ( x )$ at which the tangent line is horizontal.

A) $( 1,7 )$ and $( - 1 , - 1 )$
B) $( - 1 , - 12 )$
C) $f ( x )$ has no points with a horizontal tangent line.
D) $( 0,0 )$ and $( - 1 , - 1 )$
E) $( 3,0 )$