In epic poetry the poet often begins by asking for assistance in telling the story. this epic convention is known as the

An example of this would be the Odyssey, in which Homer asks the muses for assistance.  This 'epic convention' is known as an invocation.  In many religious settings, an invocation is a prayer to open the meeting.  This always helps me to remember, because in both examples it is a plea to a God(s) and at the beginning.

What's your question?

I’m going to guess #4 since that seems pretty logical.