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.

eat : fork. eat : ?
fork

bake : oven. spread : ?
knife

cut : sword. unlock : ?

key