What type of material is the gardener using when she refers to composted materials?

The gardener refers to composted materials as decomposed organic matter called humus. Humus is a dark, organic component of soil formed through the decomposition of plant and animal material, which enriches the soil with nutrients and enhances its ability to retain moisture. This process is crucial for creating fertile soil that supports healthy plant growth.

In contrast, the other options describe materials or conditions that do not accurately represent compost. The first option mentions a mixture of fungi, insects, and worms, which may indeed be present in compost but do not capture the essence of what composted materials are. The third and fourth options incorrectly refer to types of soil that are defined by texture or mineral composition rather than by the organic decomposition process that defines humus. Thus, the correct term for composted materials is clearly best reflected by the description of humus.