The correct answer is the size of scapulae, size of teeth, and length of the tail.
A saber-toothed cat refers to any member of numerous extinct groups of predatory mammals, which were featured by curved and long saber-shaped canine teeth. The large maxillary canine teeth elongated from the mouth even when it was closed.
The saber-toothed cats were found globally from the Eocene epoch to the termination of the Pleistocene era that is, existing for almost 42 million years.