What is a necessary condition for the fossilization of an organism's remains?

For an organism's remains to undergo fossilization, rapid coverage in sediment is vital. This process helps protect the remains from scavengers, decomposition, and environmental factors that could otherwise destroy them. When an organism is quickly buried under layers of sediment, it creates an anaerobic environment, which reduces the likelihood of decay. This covering also allows minerals carried by groundwater to seep into the remains, facilitating the gradual process of fossilization. Fossils are most often found in sedimentary rock, which forms from particles of sand, silt, clay, and other materials that settle over time. Thus, the rapid deposition of sediment is essential for preserving the details of the organism's structure, allowing it to be identified millions of years later.

The other options would not contribute effectively to the fossilization process; for instance, exposure to oxygen and high levels of light can accelerate decomposition, while extremely high temperatures could lead to the destruction of organic material rather than preservation.