Ninety-five percent of all living organisms were killed by the deadliest mass extinction in history. it is known as the mass extinction.
a. cretaceous-tertiary
b. end triassic
c. permian-triassic
d. late devonian
e, ordovician-silurian

C. Permian-Triassic.

Explanation:

It is normally known as the Great Dying and is the most severe mass extinction event in Earth´s history. It took the world about 10 million years to recover the same numbers of life previous to that.

According to the researchers, the cause of the extinction could be up to to three. A meteor impact event, massive volcano eruptions or climate changes. It could be one of those or all together.

I hope this answer helps you.