In paragraph 1, why does the author include a discussion of when flowering plants evolved? A. To help explain why some scientists believe that the development of flowering plants led to dinosaur extinction B. To cast doubt on the theory that the development of flowering plants caused dinosaurs to become extinct C. To suggest that dinosaurs were able to survive for as long as they did because of the availability of flowering plants D. To emphasize that duckbill dinosaurs and horned dinosaurs were the first dinosaurs to become extinct