Select all of the answers that apply. the cretaceous-tertiary extinction, the most famous of the big five, has been attributed to what major event(s) that triggered the extinction of the dinosaurs? an asteroid hitting the earth massive volcanoes erupting around the world rapid growth of forests on land surfaces falling sea levels increased competition from mammals

The Cretaceous-Tertiary Mass extinction is possibly the major mass extinction event, which eliminated all the dinosaurs from the Earth. This was the fifth mass extinction event and is known as the K-T extinction event in short.  

The prime cause of mass extinction is an impact by an unusual high numbers of extremely large asteroids. The impact of the asteroids themselves were not only accountable for the extinction of about 75 percent of the species, which were alive at that time, though, the enduring residual influences of the impacts were devastating.  

Other prime catastrophes directly resulted due to the impacts comprise earthquakes, tsunamis, and possibly the enhanced volcanic activity. Hence, the correct answers are an asteroid hitting the earth and massive volcanoes erupting around the world.