Which statements about best practice is MOST correct?

Customers define service requirements and expectations but do not prescribe internal operational best practices for how a service provider should structure or run its services.

Internal experience is a legitimate input to best practice development, but it is one of several sources - ITIL explicitly recognizes external frameworks, industry standards, and supplier knowledge as additional valid sources.

ITIL (IT Infrastructure Library) is developed and maintained by AXELOS as a collection of best practices drawn from public and private sector organizations globally. Its strength as a best practice source comes specifically from its validation across a wide set of environments and situations, distinguishing it from purely internal or anecdotal experience. This broad validation ensures its guidance is applicable across different organizational contexts and maturity levels.

Suppliers fulfill contractual obligations and deliver agreed services, but their role is not to define or impose best practices on the service provider's internal operations.