What does a call event represent?

What does a call event represent?

• A. Represents the receipt of a request to invoke an operation in a target structure
• B. Represents the sending of a request to invoke an operation in a target structure
• C. Represents a guard condition on a transition
• D. Represents completion of an operation

Answer: (A)

Call events capture the moment a request to invoke an operation arrives at the target object. It reflects the receiver’s side of the interaction—the callee is being asked to execute its operation. This is why it represents the receipt of a request to invoke an operation in a target structure. It isn’t about the sender issuing the request, which would be a different perspective; it also isn’t a guard condition on a transition, nor the completion of the operation, which happens after the invocation has finished.

Call events capture the moment a request to invoke an operation arrives at the target object. It reflects the receiver’s side of the interaction—the callee is being asked to execute its operation. This is why it represents the receipt of a request to invoke an operation in a target structure. It isn’t about the sender issuing the request, which would be a different perspective; it also isn’t a guard condition on a transition, nor the completion of the operation, which happens after the invocation has finished.