Identify the statement that is true about mass extinctions.
Choose one:
A. The mass extinction of dinosaurs occurred at the Cretaceous/Paleogene boundary.
B. The mass extinction of over two-thirds of the species on the Earth was the result of large volcanic eruptions in Hawaii.
C. Mass-extinction events are times in the Earth's history when few species evolve.
D. A mass extinction may happen when a comet or asteroid impact starts a chain of worldwide volcanic eruptions.

A. The mass extinction of dinosaurs occurred at the Cretaceous/Paleogene boundary.

Explanation:

The most known extinction is the associated with the Dinosaurs, which happened at the Cretaceous/Palogene boundary (66 million years ago), although there is still a huge discussion on the causes of such extinction (comet/asteroid, changes in sea level, volcano activity).

Such event meant the dissappearing of two-thirds of the living species on Earth.

what events in mexico's history might explain why the country continues to have difficulty improving social justice and economic opportunities for all people?