If X = 2 Tan θ,Use Trigonometric Substitution to Write $\sqrt { 4 + x ^ { 2 } }$

Multiple Choice

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

A) ​2 cos θ
B) ​2 tan θ
C) ​2 sin θ
D) ​2 sec θ
E) ​2 csc θ