If X = 3 Cot $\theta$ , Use Trigonometric Substitution to Write

Multiple Choice

If x = 3 cot $\theta$ , use trigonometric substitution to write $\sqrt { 9 + x ^ { 2 } }$ as a trigonometric function of $\theta$ , where $0 < \theta < \pi$ .

A) 3 sec $\theta$
B) 3 csc $\theta$
C) 3 cos $\theta$
D) 3 sin $\theta$
E) 3 cot $\theta$