Answer: Metal
Step-by-step explanation:
Metals do not degrade with time as they are not biodegradable in nature. They are not degraded easily by the effect of bacteria and natural forces.
The metals are not degraded by the bacteria so easily and it is found preserved for many years.
The body gets degraded easily by the effect of bacteria on it and will be rotten and degraded after sometime. This does not affects the metal so it will be preserved even after many years.