Answer: Option (C)
Explanation:
Mass extinction refers to the large scale depletion of species diversity, existing at any particular point in terms of geological time scale. This occurs suddenly and it traces the changing diversities of plants and animal species and their availability.
The causes of mass extinction could be due to the increasing rate of volcanic eruptions, falling of the sea level as well as due to the impact of asteroids and comets on earth.
Thus, the correct answer is option (C).