If $\large\frac{dy}{dx}=\frac{y+ x \tan \Large\frac{y}{x}}{x}$ then $\sin \large\frac{y}{x}$ is equal to :

Question

$$\begin {array} {1 1} (a)\;cx^2 & \quad (b)\;cx \\ (c)\;cx^3 & \quad (d)\;cx^4 \end {array}$$