Use the Trigonometric Substitution to Rewrite the Algebraic Expression as a Trigonometric

Multiple Choice

Use the trigonometric substitution to rewrite the algebraic expression as a trigonometric function of $\theta$ , where $0 < x < \frac { \pi } { 2 }$ . $\sqrt { 25 x ^ { 2 } + 36 } , 5 x = 6 \tan \theta$

A) 25 tan $\theta$
B) 5 tan $\theta$
C) 25 sec $\theta$
D) 6 sec $\theta$
E) - 5 sec $\theta$