Participants Are Asked to Perform an Imagery Task While Simultaneously

Participants are asked to perform an imagery task while simultaneously keeping track of a visual target (a light that varies in brightness) . The visual task will

A) disrupt the imagery task.
B) have no effect on the imagery task.
C) disrupt the imagery task if it requires visual imagery but not if the task can be done with spatial imagery.
D) cause the images to be less vivid but will have no other effects.