Which feature is characteristic of natural burials?

Natural burials emphasize environmentally friendly practices, and one of the key features of natural burials is the use of biodegradable materials for caskets and urns. This approach aligns with the philosophy of minimizing environmental impact, allowing the body and burial containers to decompose naturally and return to the earth. Biodegradable caskets might be made of materials like wood, wicker, or even cardboard, which break down over time, supporting ecological balance.

In contrast, the other options represent practices that are generally not aligned with the principles of natural burial. Elaborate caskets typically involve more materials and can be more impactful on the environment. Chemical treatments of the body, such as embalming, are also contrary to the ethos of natural burials, as they often utilize harmful substances that can hinder natural decomposition. Lastly, while cremation is a separate disposition method, it does not necessarily relate to natural burials, which focus specifically on in-ground options that avoid such processes. Therefore, the emphasis on biodegradable materials is what makes option C characteristic of natural burials.