REM Sleep Is Sometimes Referred to as "Paradoxical" Sleep Because

REM sleep is sometimes referred to as "paradoxical" sleep because:

A) there is much tossing and turning but the brain is relatively inactive.
B) aspects of all four stages of sleep occur during REM sleep.
C) it is the only stage in which people have both good dreams and night terrors.
D) the body and brain are aroused but there is little physical movement.