The answer is only "whichever", but in rare cases when you personify places, can "whoever" be an answer as well?
gr51)Since 1988, Outback Steakhouse has been known for its exceptional food an quality service. We serve the freshest food possible, using only the highest quality ingredients. Just click on the map to find the Outback Steakhouse nearest you. ____________ you visit, we'll serve you the best food.
1)Whoever 2)Whichever 3)Whatever 4) However
* The map is an entire American map.