science question lol i need help
What evidence is most consistent with dinosaurs becoming extinct at the end of the Cretaceous era?
A). Mammal fossils are rare in the Cretaceous era and and numerous in the Paleogene era.
B). No dinosaur fossils are found above the Cretaceous-Paleogene boundary.
C). The Cretaceous-Paleogene boundary layer contains few or no fossils.
D). Dinosaur fossils are not found in the oldest rocks on Earth.