A, this is my guess because topsoil is made mostly of humus(sand, silt, clay and broken down organic matter) and the rest of the answers don’t make sense, hope this helps :]
Answer:
The answer is to send away
Process # 1. Removal of Suspended & Dissolved Impurities:
Removal of coarse, dispersed and colloidal impurities from water is known as clarification. These impurities may be removed either by filtration or by sedimentation.
It is important because if it is active, it gives the best info!
