2. In paragraph 2, why does the author include the information that dinosaurs had flourished for tensof millions of years and then suddenly disappeared?
(A) To support the claim that the mass extinction at the end of the Cretaceous is thebest-documented of the dozen or so mass extinctions in the geological record
(B) To explain why as many as half of the species on Earth at the time are believed to have becomeextinct at the end of the Cretaceous
(C) To explain why paleontologists have always been intrigued by the mass extinction at the end ofthe Cretaceous
(D) To provide evidence that an impact can be large enough to disturb the environment of the entireplanet and cause an ecological disaster