Answer: B horizon
Step-by-step explanation:
Soluble minerals and clays build up in the B horizon or subsurface. Due to the iron and clay minerals present, this layer is a brighter shade of brown and retains more water than the topsoil. Less organic matter is present.
They are an area of accumulation where material from above has been leached by rainwater flowing through the soil and precipitated inside the B layers, or the material may have weathered in place. Compared to the original parent material, a soil B horizon is a mineral horizon that has undergone processes that alter its physical or chemical composition.
The organic matter content of the B horizon is lower than that of the topsoil, and it frequently contains more clay. The solum is the collective name for the A, E, and B horizons. The majority of plant roots grow in this region of the profile.