"At which stop does the bus arrive?"
Translation:Hányadik megállóba érkezik a busz?
Or very nearly correct.
Szép a megálló, amelynél/aminél állunk.
Aminél állunk, az egy buszmegálló - What we are standing by is a bus stop.
With a few exceptions, "ami" should be used when the referred object is not named, like in the sentence above.
Here is the extended discussion, for those interested:
Shouldn't the English sentence be Continuous? Without time designation it's supposed to be happening now.