Which of the Following Statements Is Correct on Workflow Events

Which of the following statements is correct on workflow events?

A) A predefined (or file-wait) Event Wait task waits for a file to appear at the specified location. As soon as the file appears, the event succeeds and the file can be processed by the subsequent mapping
B) A user-defined event can be created a-d raised in one workflow and then used In another
C) A predefined (or file-wait) Event Wait waits for a file to appear at the specified location. As soon as the file appears, it is deleted and the subsequent task will start.
D) A user-defined event can be created in either the Event Wait or Event Raise task