Fred Is Having a Vivid Dream About Running in a Marathon

Fred is having a vivid dream about running in a marathon. His body does NOT mimic this running because:

A) Fred is able to voluntarily control his muscle movements during this dream.
B) the level of arousal in the body and the activity of the brain are significantly less during REM sleep so physical movement is impossible.
C) dreaming has been found to take place only in the prefrontal lobe and doesn't affect any other areas of the brain or body.
D) even though our brains are very active, we are essentially paralysed while in REM sleep.