The passage suggests that if the researchers had not found that two extinct carnivore spec

ies were free of tooth breakage, the researchers would have concluded that______

A．the difference in breakage frequencies could have been the result of damage to the fossile remains in the La Brea pits

B．the fossils in other Pleistocene sites could have higher breakage frequencies than do the fossils in the La Brea pits

C．Pleistocene carnivore species probably behaved very similarly to one another with respect to consumption of carcass

D．all Pleistocene carnivores species differed behaviorally from present-day carnivore species.

E．predator desities during the Pleistocene era were extremely high