Find the X Coordinates of All Relative Extreme Points Of f

Multiple Choice

Find the x coordinates of all relative extreme points of $f ( x ) = \frac { 1 } { 4 } x ^ { 4 } + \frac { 2 } { 3 } x ^ { 3 } - \frac { 3 } { 2 } x ^ { 2 } + 4$

A) x = -3, 0, 1
B) x = -1, 0, 3
C) x = -3, 1
D) x = 0
E) x = -1, 3