Which one of the following is the BEST description of a service-based service level agreement (SLA)?

Covering all services used by a single customer group is the definition of a customer-based SLA, not a service-based SLA.

An agreement covering one service for a single customer is a more granular arrangement that combines aspects of both service-based and customer-based structures, which is not the standard definition.

Describing service-specific issues within a multi-level SLA structure refers to a component layer of a multi-level SLA, not the standalone definition of a service-based SLA.

In ITIL, a service-based SLA is an agreement structured around a single service and applied uniformly to all customers using that service. This approach reduces the number of individual agreements required when multiple customer groups consume the same service under identical terms. It contrasts with a customer-based SLA, which is tailored to a specific customer group.