Where would you get a ball if you do not have one?
sporting event sporting goods store bowling alley
sporting goods store
the answer, "sporting goods store" would be the best because a bowling alley does nto generally have balls for people to keep or buy and a sporting event would be a time for people to bring a ball they own, a "sporting goods store" would be the best option due to the variety and volume.
get a ball if you do not have one