The term callee save denotes the case where the (calling / called) program saves the contents of registers whose contents will be changed during the invocation of the called program

The right approach is "called". The further explanation is described below.

Explanation:

Callee saved suggests that whenever the feature returns or exists, the callee needs to save other registrations and afterward recover them at either the conclusion of the conversation even though they have the promise for the caller just to maintain these very same values. It's indeed necessary to retrieve them, even though at any stage mostly during call individuals are pummeling.