For What Values Of $c$ Does the Curve Have Maximum and Minimum Points for the and Minimum

Multiple Choice

For what values of $c$ does the curve have maximum and minimum points for the given function $f ( x ) = 2 x ^ { 3 } + c x ^ { 2 } + 8 x ?$

A) $c = \pm \sqrt { 33 }$
B) $c = \pm 4 \sqrt { 3 }$
C) $- 4 \sqrt { 3 } < c < 4 \sqrt { 3 }$
D) $c < - 4 \sqrt { 3 } , c > 4 \sqrt { 3 }$
E) $c \langle - \sqrt { 33 } , c \rangle \sqrt { 33 }$