During his dream last night herbie imagined he was able to fly and jumped off of the roof, flying around his home town. he awoke in his bed, and clearly had not moved all night. why didn’t he try to fly with his body if his brain was so active? a) herbie's circadian rhythms kept him asleep b) herbie was dreaming during rem sleep c) herbie does not experience sleep walking, and therefore has an abnormal sleep cycle d) dreams happen during the awake-aroused part of the sleep cycle