<h3>
Answer:</h3>
24-hour. Suprachiasmatic nucleus
<h3>
Explanation:</h3>
The internal clock for humans is accurate to within a few minutes for most people. However, it tends to run on a 24-hour clock, and therefore must be reset each day. The brain region that is responsible for resetting the internal clock is the suprachiasmatic nucleus.
The reason why "24-hour" is the correct answer because the "24 hour" clock is the standard clock that most things go by.
The reason why "suprachiasmatic nucleus" is the correct answer because this is the part of the brain that is responsible for resetting the internal clock.
The suprachiasmatic nucleus controls the "circadian rhythm", in other words, it controls the 24-hour cycle in our body. It controls the time in which we sleep and works with the "circadian rhythm" in order to improve our behavior through out the day.
<h3>I hope this helped you out.</h3><h3>Good luck on your academics.</h3><h3>Have a fantastic day!</h3>