Solve the Following Equation $9 \cot ^ { 2 } x - 3 = 0$

Multiple Choice

Solve the following equation.​ $9 \cot ^ { 2 } x - 3 = 0$ ​

A) ​ $\frac { \pi } { 2 } + n \pi , \frac { 2 \pi } { 5 } + n \pi$
B) ​ $\frac { \pi } { 3 } + n \pi , \frac { \pi } { 3 } + n \pi$
C) ​ $\frac { 4 \pi } { 3 } + n \pi , \frac { 2 \pi } { 3 } + n \pi$
D) ​ $\frac { 2 \pi } { 3 } + n \pi , \frac { 2 \pi } { 3 } + n \pi$
E) $\frac { \pi } { 3 } + n \pi , \frac { 2 \pi } { 3 } + n \pi$