If $x = 2 \cot \theta$ , Use Trigonometric Substitution to Write

Multiple Choice

If $x = 2 \cot \theta$ , use trigonometric substitution to write $\sqrt { 4 + x ^ { 2 } }$ as a trigonometric function of $\theta$ , where $0 < \theta < \pi$ .

A) $2 \cos \theta$
B) $2 \csc \theta$
C) $2 \cot \theta$
D) $2 \sec \theta$
E) $2 \sin \theta$