Which Statement Concerning REM Sleep Is True

Multiple Choice

Which statement concerning REM sleep is true?

A) During the REM stage, delta waves are emitted.
B) Most people spend almost all of their sleep time in the REM stage.
C) The preoptic area of the hypothalamus stimulates REM sleep.
D) During REM sleep, blood flow to the entire brain decreases.
E) REM sleep is absolutely necessary, as a lack of this stage causes anxiety and irritability.