Is the definition of synthetic? Is it not real or a copy

Explanation:

Synthetic is something that is not made from natural materials but rather made from the synthesis of other materials in a lab. This is mostly done in clothing where you have some natural materials like cotton and other materials that are synthetic. This doesn't mean it is not high quality. It is actually preferable for some sports for example to wear synthetic clothing instead of cotton.

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."