Percy is injected with a drug that paralyzes his eye muscles. When he is instructed to try to move his eye when looking a stationary scene, his brain is able to send a signal to his eye muscles but he is unable to move his eyes. As a result, he perceives _____.
a. no movement, because his eye muscles can't move
b. no movement, because the scene is stationary
c. movement, because there is a CDS and an IDS
d. movement, because there is a CDS, but not an IDS