Answer: D. Replacing thermal power plants.
Explanation:
Thermal Power Stations are some of the biggest users of water in the world because water is integral to producing electricity in them. These stations burn fossil fuels like coal which then vaporizes water so that it becomes steam which then drives turbines that produce electricity.
Water is also used for cooling high temperatures produced.
If these thermal stations are replaced with something that uses less water, it will go a long way in keeping the water debt less than the water supply.
They observe it, run tests on many different things, and do expirments
The main function of mitosis is to allow for growth and development and to replace dead and or decayed tissue.
Geocentric - Earth Centered solar system
Heliocentric - Sun Centered solar system