2 ( 1 + ta n^2 ) simplifies to?

Answer: Option C

$$\begin{array}{rl}& =\frac{2\sin \theta }{\cos \theta \left(1+\text{ta}{\text{n}}^2\theta \right)}\\ & =\frac{2\text{tan}\theta }{1+\text{ta}{\text{n}}^2\theta }\\ & =\sin 2\theta \end{array}$$