General solution of differential equation: $\large\frac{xdy}{x^2+y^2} $$+\bigg(1- \large\frac{y}{x^2+y^2} \bigg)$$dx=0$ is

Question

$(a)\;x^2+\tan^{-1}(\frac{y}{h})=c \\ (b)\;x+\tan^{-1} (\frac{x}{y})=c \\ (c)\;x^2-\tan^{-1}(\frac{y}{x})=c \\ (d)\;x-\tan^{-1} (\frac{x}{y})=c $