If a Service Can Have One or More Service Capabilities

If a service can have one or more service capabilities, then how can a service consumer interact with a service?

A) It can't. The service must only provide one service capability in order for it to be accessible by service consumers.
B) Each service capability represents a function that the service has to offer. The service consumer can invoke and interact with one service capability at a time, thereby only using a subset of the service's overall functionality.
C) Service capabilities are designed to be composed together, which means that in order for a service consumer to interact with a service, it must be designed to invoke all of its service capabilities at the same time.
D) Services do not have service capabilities that are explicitly invoked. Services almost always exist as event-driven programs that transparently intercept service consumer messages at runtime.