Ause-case diagram is a staticdiagram?

No, Use-Case diagram is a not a static diagram.

Explanation:

Only static diagram is not adequate to model a system that is more dynamic than static behavior. In Unified Modeling Language, five diagrams are accessible to model the dynamic nature and use case diagram is one of them.

Use case diagrams is made up of actors, use cases and their interactions. The diagram is used for modeling an application's system / subsystem. A single use case diagram depicts a system's specific features.

answer; i believe its compare (b3: b4) ;