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.

[EX Q]: stir : spoon. clamp : ?
[EX A]: clamp

[EX Q]: cut : knife. stir : ?
[EX A]: spoon

[EX Q]: eat : spoon. unlock : ?
[EX A]:
key