Which of the following best characterizes a night’s sleep? A. We begin the night in light sleep and end in deep sleep. B. We pass from light sleep to dream sleep to deep sleep. C. Our depth of sleep...

Which of the following best characterizes a night’s sleep?

A. We begin the night in light sleep and end in deep sleep. B. We pass from light sleep to dream sleep to deep sleep. C. Our depth of sleep alternates up and down many times. D. We alternate from the waking state to dream sleep about six times.