Ship X and ship Y are 5 miles apart and are on a collision course. Ship ... ...

Ship X and ship Y are 5 miles apart and are on a collision course. Ship X is sailing directly north, and ship Y is sailing directly east. If the point of impact is 1 mile closer to the current position of ship X than to the current position of ship Y, how many miles away from the point of impact is ship Y at this time?
(A)    1
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Nova Math - Problem Set J: Geometry