What temperature range is required for an adult body to be reduced to ashes?

The correct temperature range required for an adult body to be reduced to ashes is 1800-2000 degrees Fahrenheit. At these temperatures, organic materials are completely incinerated, and the remains are reduced to ash. This range ensures that not only the soft tissue is consumed but also the bones are turned into bone ash, which is the only residue left after the cremation process.

Cremation requires high temperatures to ensure a thorough and complete reduction of body material. Temperatures below this range, such as those indicated in the other choices, would likely result in incomplete combustion, leaving behind unburned remnants or larger pieces of bone, which would not qualify as ash. Consequently, the process is carefully regulated to achieve these high temperatures necessary for effective cremation.