Answer: i think its C. but find another source just in case.
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.
Explanation:
Many scientists believe that RNA, or something similar to RNA, was the first molecule on Earth to self-replicate and begin the process of evolution that led to more advanced forms of life, including human beings.
The main causes of climate change are: Humanity's increased use of fossil fuels – such as coal, oil and gas to generate electricity, run cars and other forms of transport, and power manufacturing and industry. Deforestation
Volcanologists can predict eruptions—if they have a thorough understanding of a volcano's eruptive history, if they can install the proper instrumentation on a volcano well in advance of an eruption, and if they can continuously monitor and adequately interpret data coming from that equipment.
Gravity is the force of attraction that occurs between two objects due to their mass.
Bone marrow produces many types of white blood cells.