What percentage of all living things that have ever existed on
earth are now extinct?
a. 50 percent
b. 70 percent
c. 85 percent
d. 99 percent

The correct answer option is d. 99 percent.

Explanation:

Extinction is the term used for the termination of any organism or of a group of organisms which are commonly called as species.

Death of organisms or a species results in their extinction. Out of all over five billion species that have ever existed on the earth, about 99 percent have already gone extinct.

While the current number of species that exist on earth have reduced to a range of 10 million to 12 million.