Find $\large\frac{dy}{dx}$ of the function $xy = e^{\large(x-y)}$

Question

$\begin{array}{1 1} \large\frac{y(y-1)}{x(1+y)} \\ \large\frac{y(x+1)}{x(1-y)} \\ \large\frac{x(x-1)}{y(1+y)} \\ \large\frac{y(x-1)}{x(1+y)} \end{array}$