Question

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sleep in which heart rate, breathing, and brain activity are steady

irregular or rapid - eye - movement sleep

regular or nonrem sleep

visual acuity

waking activity

alert inactivity

Explanation:

Non - REM sleep is characterized by steady heart rate, breathing, and brain activity. Rapid - eye - movement (REM) sleep has more variable physiological activity. Visual acuity pertains to vision, waking activity is when awake, and alert inactivity is not related to sleep with steady physiological states.

Answer:

regular or nonREM sleep