Answer: B horizon
Explanation: Illuviation is the process whereby materials and particles from one soil layer are absorbed into another layer. This follows an eluviation process which is responsible for displacing the materials in the first place.
The B horizon is the second layer of the soil after A horizon, the layer which is exposed to organic materials and which is the primary way the soil absorbs materials. When material are lost by this layer, they seep into the B horizon.
