Considering a library management system,

a$)$ List three actors. Explain the relevance of each actor.

b$)$ One use case is to checkout book$($s$).$ List four additional use cases at a comparable level of abstraction$.$

Summarize the purpose of each use case with a sentence.

c$)$ Prepare a use case diagram for a library management system.

d$)$ Prepare a class diagram for this library management system from use case diagram.