Let each of the equations \(x^{2}+2 x y+a y^{2}=0 \& a x^{2}+2 x y+y^{2}=0\) represent two straight lines passing through the origin. If they have a common line, then the other two lines are given by
(A) \(x-y=0, x-3 y=0\)
(B) \(x+3 y=0,3 x+y=0\)
(C) \(3 x+y=0,3 x-y=0\) (D) \((3 x-2 y)=0, x+y=0\)