An asteroid struck Earth, altering the environmental conditions and leading to the extinction of many species, including dinosaurs.
B
Changes in global temperatures imposed stress on the dinosaurs and they could not adapt fast enough to survive and reproduce.
C
All dinosaurs lived in an isolated area. An asteroid struck this area, killing many dinosaurs. There were not enough survivors to maintain the species over time.
D
Dinosaurs that ate plants competed for food with too many other organisms. Due to their size, they could not find enough food to survive.