The differential equation formed by eliminating $A$ and $B$ from the relation $y=e^{x}(A\cos x+ B\sin x)$ is

Question

$$\begin{array}{1 1}(1)y_{2}+y_{1}=0&(2)y_{2}-y_{1}=0\\(3)y_{2}-2y_{1}+2y=0&(4)y_{2}-2y_{1}-2y=0\end{array}$$