Say someone is holding a number of items in front of you. What would you call the action you request that they perform to remove all choices but one so that you can examine the item that is left? It is important that the phrase let the other person know which item you want to be left standing.
Better, if it makes a difference, what is the action you perform on the object itself to get rid of its siblings?
For example, you say "Could you [blank] that item?" and they will remove the others.