Find $\frac {dy}{dx}$ in the following:$y = sin^{-1} \left(\frac{1 - x^2}{1 + x^2}\right), 0 < x < 1$

Question

$\begin{array}{1 1} \large\frac{-2}{1+x^2} \\ \large\frac{2}{1+x^2} \\ \large \frac{-2x}{1+x^2} \\ \large\frac{2x}{1+x^2}\end{array}$