According to circadian rhythms, the body is most susceptible to sleep at which time of day?

• A. Early evening, around 6:00 p.m.
• B. Late at night, typically between 2:00 a.m. and 4:00 a.m.
• C. Midday, around 12:00 p.m.
• D. Late morning, around 10:00 a.m.

Answer: (B)

Verified step by step guidance

1. Understand that circadian rhythms are natural, internal processes that regulate the sleep-wake cycle and repeat roughly every 24 hours.
2. Recognize that the body has periods of increased sleepiness and alertness influenced by these rhythms, often linked to environmental cues like light and darkness.
3. Identify that the body’s core temperature and melatonin levels fluctuate throughout the day, affecting sleepiness.
4. Note that the body is typically most susceptible to sleep during the early morning hours, when melatonin levels peak and core body temperature is at its lowest.
5. Conclude that this period usually falls between 2:00 a.m. and 4:00 a.m., making it the time when the body is most inclined to fall asleep according to circadian rhythms.