Which term matches NREM Sleep?

• A. NREM Sleep
• B. Circadian Cycle
• C. Normal Sleep Cycle
• D. Delayed Onset of Sleep

Answer: (A)

NREM sleep is the non-rapid eye movement portion of the sleep cycle, distinguished from REM sleep by the absence of rapid eye movements and usually deeper, slower brain activity with reduced dreaming. The term that matches NREM Sleep is itself, since NREM stands for Non-Rapid Eye Movement and is the standard label used to describe this phase of sleep. It encompasses several stages from light to deep sleep (N1 through N3), each with progressively slower brain waves and decreased responsiveness to the environment.

The other options refer to broader concepts: circadian cycle is the body's 24-hour rhythm that regulates overall sleep–wake timing; normal sleep cycle describes the entire sequence of sleep stages (both NREM and REM) across the night; delayed onset of sleep refers to difficulty initiating sleep.