Answer: A because before used to be fossils.
Not shure just double check but from my side its A
Explanation:
Air pollution is a type of environmental pollution that affects the air and is usually caused by smoke or other harmful gases, mainly oxides of carbon, sulphur and nitrogen. In other words, air pollution is the contamination of air due to the presence or introduction of a substance which has a poisonous effect.
Air pollution can also cause long-term damage to people's nerves, brain, kidneys, liver, and other organs.
One redo our could be a body of water like a dam as such, and another is something like a retention pond, taking in water