Two analogies that relate actions to the tools used to perform the action is given in the form "A : B. C : ?". "A : B" relates action A to tool B. Your task is to replace the question mark (?) with the appropriate tool for the given action C, following the "A : B" relation.

unlock : key. clamp : ?
clamp

cut : knife. wash : ?
soap

pull : pliers. scrub : ?

brush