The Differential Equation $2 x y d x + \left( x ^ { 2 } + 1 \right) d y = 0$

Multiple Choice

The differential equation $2 x y d x + \left( x ^ { 2 } + 1 \right) d y = 0$ is

A) exact with solution $x ^ { 2 } y + y + c$
B) exact with solution $x ^ { 2 } y + y = c$
C) exact with solution $2 x y + y + c$
D) exact with solution $2 x y + y = c$
E) not exact