Find $\large \frac{dy}{dx}$ when x and y are connected by the relation $\tan^{-1}(x^2+y^2)=a$

Question

$\begin{array}{1 1}(A)\;\large\frac{y}{x}\\(B)\;\large\frac{-y}{x}\\(C)\;\large\frac{x}{y}\\(D)\;\large\frac{-x}{y}\end{array}$