Correct Answer - C
If ion is positive then, it will acquire velocity in `(+ve)` x direction and hence magnetic force will act in `-y` direction `F_(M)=q(vec(v)xxvec(B))` for `(-)` ion. It will acquire velocity in `-x` direction due to electric field and hence magnetic force will act ion `-y` direction because charge is negative . Hence in both the case ions will deflect in `(-ve)` y direction.