Answer:
D) It decreases water movement.
Step-by-step explanation:
Humus is known as part of the soil formation. It is characterized by various qualities some of which include containing nutrients such as nitrogen. It is also characterized by its ability to retain water content or soil moisture. Humus is made from the decays of plants wastes such as leaves.
Hence, in this case, the correct answer is Humus is important because "It decreases water movement."