___ is(are) described as slow-wave sleep.
A. stage 1
B. stage 2
C. stage 3 and stage 4
D. REM sleep
Answer: c. Stage 3 and stage 4
___ is(are) described as slow-wave sleep.
A. stage 1
B. stage 2
C. stage 3 and stage 4
D. REM sleep
Answer: c. Stage 3 and stage 4