B because the temperature goes up then the birds would move to the south were it is cooler.
Biotic factors are anything in a ecosystem that is living, was living, or is going to live.
From this we can conclude that the biotic factors are remains of dead organisms and flora and fauna.
Temperature and minerals in the soil are abiotic, meaning they will never live.
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.