What are common indications for the use of melatonin?

Correct answer is C) Regulation of the sleep-wake cycle. Melatonin is commonly indicated for the regulation of the sleep-wake cycle, especially in cases where there is a disruption in the circadian rhythm. It is often used to address issues such as jet lag, shift work sleep disorder, and certain types of insomnia. Melatonin does not have indications for treating bacterial infections, chronic pain, or high blood pressure.