Evaluate the Integral $$\int _ { - \pi / 4 } ^ { \pi / 4 } 3 \sinh ( \tan \theta ) \sec ^ { 2 } \theta d \theta$$

Multiple Choice

Evaluate the integral.
- $$\int _ { - \pi / 4 } ^ { \pi / 4 } 3 \sinh ( \tan \theta ) \sec ^ { 2 } \theta d \theta$$

A) 3
B) 0
C) $3 \left( e - \frac { 1 } { e } \right)$
D) $3 \left( e ^ { \pi / 4 } - e ^ { - \pi / 4 } \right)$