Extinction of existing species: Group of answer choices

a. Is an unconformity. Occurred at a low level throughout geologic history.

b. Occurred only at times of catastrophic mass extinctions.

c. Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times.

d. Is a process that happened in the past but cannot happen today.

The correct answer is C. Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times.

Explanation:

Extinction occurs as a species or group of organisms permanently disappears; this implies there would not be new individuals of the same species. Extinction is considered as a natural process that occurs as the result of changes in the environment, competition, predators, natural disasters, among others.

Additionally, during the geologic history extinction has been a common factor as most of the species that ever lived have now disappeared. However, extinction levels have changed over time because during mass extinctions the rate of extinction increases massively, which means many species disappear in a short time. But the rest of the time extinction is constant and occurs at a low level.