\begin{array}{1 1}(A)\;\frac{d^2y}{dx^2}-2\frac{dy}{dx}=0 & (B)\;\frac{d^2y}{dx^2}-2\frac{dy}{dx}+2y=0\\(C)\;\frac{d^2y}{dx^2}+2\frac{dy}{dx}+2y=0 & (D)\;\frac{d^2y}{dx^2}+2y=0\end{array}