Which action waits for an asynchronous event before continuing?

• A. Accept event action.
• B. Wait time action.
• C. Send signal action.
• D. Call behavior action.

Answer: (A)

Waiting for an asynchronous event before continuing is modeled by an Accept Event Action. This kind of action represents a pause in the workflow that holds until a specific external event occurs—like a message arriving or a sensor signal—at which point the process resumes. It captures the idea of waiting for something to happen independently of a fixed timer.

In contrast, a wait time action simply delays the flow for a set duration, regardless of any events. A send signal action produces a signal to others but does not pause for something to happen. A call behavior action starts another behavior and the flow continues according to the completion of that behavior, not because an external event occurred.