Which of the following methods can lead to the decomposition of organic materials?

The appropriate method leading to the decomposition of organic materials is decomposition itself. Decomposition is a natural process whereby microorganisms break down dead organic matter, returning nutrients to the ecosystem. This process is facilitated by bacteria, fungi, and other decomposers that feed on the organic material, resulting in the breakdown of its complex molecules into simpler substances.

While preservation and embalming are methods designed to slow down or temporarily halt the decomposition process to maintain the appearance of bodies for viewings and funerals, they do not contribute to decomposition. Preservation generally involves chemical methods to inhibit microbial growth, while embalming uses specific fluids to disinfect and preserve the body. Fermentation, on the other hand, is a specific type of metabolic process that can occur under anaerobic conditions (absence of oxygen) and is not synonymous with the broader concept of decomposition.

Thus, decomposition is the only method listed that inherently causes the breakdown of organic materials, making it the accurate choice.