What Most Likely Caused the Cretaceous Mass Extinction

Question

What most likely caused the Cretaceous mass extinction?
A) a volcano
B) a flood
C) an earthquake
D) an asteroid

Accepted Answer

The most widely accepted cause of the Cretaceous mass extinction is an asteroid impact. This theory is supported by evidence such as the Chicxulub crater in the Yucatán Peninsula and a worldwide layer of iridium, an element more common in asteroids than in the Earth's crust, dating back to the time of the extinction event.