Solve the Differential Equation $$x \frac { d y } { d x } = \frac { \cos x } { x ^ { 2 } } - 3 y , x > 0$$

Multiple Choice

Solve the differential equation.
- $$x \frac { d y } { d x } = \frac { \cos x } { x ^ { 2 } } - 3 y , x > 0$$

A) $y = x ^ { 3 } ( \sin x + C ) , x > 0$
B) $y = x ^ { - 3 } ( \sin x + C ) , x > 0$
C) $y = x ^ { - 3 } ( \cos x + C ) , x > 0$
D) $y = x ^ { 3 } ( \cos x + C ) , x > 0$