Melatonin is a __________

A) hormone.
B) sleeping pill.
C) depressant.
D) stimulant.

Melatonin

A hormone produced by the pineal gland in the brain, involved in regulating sleep-wake cycles.

Sleeping Pill

A medication used to induce or maintain sleep.

Depressant

A category of drugs that reduce neural activity and slow down the functions of the brain and body.