The correct answer is the suprachiasmatic nucleus of the hypothalamus. The suprachiasmatic nucleus, as the name suggests, is the part of the hypothalamus located in right above above the optic chiasm. The main function of the suprachiasmatic nucleus is mainly responsible for the circadian rhythm of the body therefore the physiological activity on daily cycles.
So every organism is individually classified without the worry of mixing up two organisms like a fly and nat.
The answer is C. The Experiment!!!!!
It changes because the age increases