Answer:
The correct option is D) the natural extinction rate
Explanation:
Extinction can be described as a process due to which species get removed from the world.
Background extinction can be described as the standard rate of extinction of organisms of a species due to ecological or environmental factors. It is a low-level type of extinction which occurs over a long period of time. It can be described as the natural extinction rate of individual organisms. Hence, option D best describes the natural phenomenon of background extinction.
