Find the Exact Solutions of the Given Equation in the Interval

Multiple Choice

Find the exact solutions of the given equation in the interval [0, 2 $\pi$ ) . $\cos 2 x + 3 \cos x + 2 = 0$

A) $x = 0 , \pi , \frac { 2 \pi } { 3 } , \frac { 5 \pi } { 3 }$
B) $x = \pi , \frac { \pi } { 3 } , \frac { 5 \pi } { 3 }$
C) $x = \pi , \frac { 2 \pi } { 3 } , \frac { 4 \pi } { 3 }$
D) x = 0
E) $x = 0 , \pi , \frac { \pi } { 3 } , \frac { 4 \pi } { 3 }$