D. He has an aerator that pumps bubbles into the tank
Cellular respiration is the process by which many organisms, including plants, produce ATP. During this process, A.Glucose reacts with B.Oxygen, producing C. Carbon dioxide, D. Water, and ATP.
The hormone described above is the hormone Melatonin.
Melatonin is a hormone secreted by the pineal gland in the brain, which helps regulate other hormones and maintains the body's circadian rhythm. This rhythm is an internal 24 hour clock that plays a critical role when we fall asleep and when awake. When it is dark the body releases more melatonin.