The differential equation $2xydx(x^{2}1)dy=0$ is

A$)$ exact with solution $x^{2}yy=c$

B$)$ exact with solution $x{y}^{2}y=c$

C$)$ exact with solution $2xyy=c$

D$)$ exact with solution $2xyx=c$

E$)$ not exact