Which of the following correctly compares ornithischian and saurischian dinosaurs?
a. the ornithischian clade contains the sauropod dinosaurs, while the saurischian clade contains the theropod dinosaurs.
b. members of both the ornithischian and saurischian clades evolved the capability to fly.
c. ornithischian dinosaurs had leaf shaped teeth, while saurischian dinosaurs had longer and more articulated necks.
d. all ornithischian dinosaurs were herbivores, while all saurischian dinosaurs were carnivores.

The option c is partly correct.

Explanation:

None of the statements is completely accurate because:

a. Saurischian dinosaurs include theropod and sauropod dinosaurs, and their common ancestors. Ornithischians comprise neornithischians (ornithopods and ceratopsians), thyreophorans (ankylosaurs and stegosaurs) and heterdontosaurids.

b. Capability to fly has only been documented in fossils belonging to Saurischia (where the birds are also classified in). Feathers, on the other hand, do appear in the two clades. Feathers, however, are not a trait exclusively associated to flight.

c. This is a correct comparison between ornithischians and saurischians in the sense that the attributes do belong to these clades, but when comparing animals there most be a comparison that reflects a pattern. Ornithischians have leaf shaped teeth suited to eat plant material, whereas saurischians have teeth for a carnivore and herbivore diet.

d. Sauropods are saurischians and they evolved herbivory from a meat-eater ancestor.

yes, because even though a theory has a  lot of evidence to support it, it is not always true