Two analogies that signify affordances are given in the form "A : B. C : ?". Affordance is the possibility of an action being done on an object, for example book is an affordance of writing. The phrase "A : B" implies that B is an affordance of A. Your task is to replace the question mark (?) with the appropriate affordance of the given action C, following the "A : B" relation. Your answer should be a single object without further explanation.

[Q]: write : letter. cure : ?
[A]: disease


[Q]: swear : oath. open : ?
[A]: door


[Q]: hunt : boar. fire : ?
[A]:
employee