A service is usually offered as part of a bundled package of services with a core service and one or more services. supplementary credence zone of tolerance

A, supplementary

Explanation:

A supplementary service can be said to be an added service to an original service package.

That is, a supplementary service can be said to be an extra service or services that is embedded in a whole service.

For example, when you go to a tech store to have your hard drive replaced, a supplementary service such as general cleaning and routine check of your computer is included in the hard drive replacement service.

The main or core service is hard drive replacement while the supplementary service includes cleaning and routine check of other computer components.

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