Question

The Cretaceous-Tertiary extinction, the most famous of all the Big Five, has been attributed to what major event that triggered the fall of the dinosaurs? an asteroid hitting the earth increased competition from mammals rapid growth of forests on land surfaces glaciation

Answer 1

I believe it is an astroid hitting the earth

Answer 2

The most popular explanation for the extinction of the dinosaurs was an asteroid hitting the Earth.

A piece of evidence for this is a layer of rock with properties similar to those found in an asteroid that falls in line with when the dinosaur extinction occurred.

Hope this helps!!