The correct answer is Option (2) -Fragmentation

Fragmentation is the process in which detritivores (organisms that feed on detritus) break down detritus into smaller particles. Detritivores play a crucial role in breaking down organic matter into smaller components, facilitating further decomposition and nutrient cycling in ecosystems.

By the process of leaching, water-soluble inorganic nutrients go down into the soil horizon and get precipitated as unavailable salts. Bacterial and fungal enzymes degrade detritus into simpler inorganic substances. This process is called as catabolism. Humification leads  to accumulation of a dark coloured amorphous substance called humus that is highly resistant to microbial action and undergoes decomposition at an extremely slow rate. Being colloidal in nature it serves as a reservoir of nutrients. The humus is further degraded by some microbes and release of inorganic nutrients occur by the process known as mineralisation.