Solve the Equation on the Interval [0, 2π) $$\cos ^ { 2 } x + 2 \cos x + 1 = 0$$

Multiple Choice

Solve the equation on the interval [0, 2π) .
- $$\cos ^ { 2 } x + 2 \cos x + 1 = 0$$

A) $\pi$
B) $2 \pi$
C) $\frac { \pi } { 2 } , \frac { 3 \pi } { 2 }$
D) $\frac { \pi } { 4 } , \frac { 7 \pi } { 4 }$