Which is the BEST definition of a supplier?

It is a third party responsible for supplying goods or services that are required to deliver IT services

It is a shared services unit that is responsible for supplying goods or services that are required to

deliver IT services

It is a third party with responsibility for supplying goods or services that is agreed through an

operational level agreement

It is a mixture of internal and external parties that are responsible for providing goods and services to its customer group