Find A such that the equation

$[x^3-x^{2}y-x{y}^2-y^3]+[-\frac{1}{3}{x}^3+A{x}^{2}y-3x{y}^2]\frac{dy}{dx}=0$

$.$is exact

None of the given answers

$A=\frac{1}{3}$

$A=1$

$A=-1$

$A=-3$