TASK DEFINITION: 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.
PROBLEM: pull : pliers. crack : ?

SOLUTION: nutcracker

PROBLEM: iron : iron. mop : ?

SOLUTION: mop

PROBLEM: cook : stove. unlock : ?

SOLUTION:
key