Mrs. Palmer held up a plant with its roots attached during a science lesson. She passed around a sample of the soil that the plant was growing in. She said that plant roots had grown down easily in this type of soil. This type of soil is also a mixture of sand, silt, and clay. What type of soil is Mrs. Plamer describing to her class?
A) humus
B) loam
C) subsoil
D) topsoil