The Axis of Action Is

The axis of action is

A) an imaginary vertical line down the center of the screen around which the characters are placed to preserve graphic continuity.
B) an imaginary line between the main characters that determines where the camera should be placed to preserve continuity.
C) an imaginary line between the main character and the camera that determines where the camera should be placed for close-ups.
D) a chalk line marked on the floor to show how far away from the camera the actor should be.