Final answer:
None of the given options correctly represent the clades that constitute the Sauropodomorpha, as it is a distinct clade under the Saurischia, which includes long-necked dinosaurs like Apatosaurus and does not include the Ornithischia, Theropoda, or itself in combination with other groups.
Step-by-step explanation:
The clades that constitute the Sauropodomorpha are specifically the Saurischia, not the Ornithischia nor the Theropoda. The Sauropodomorpha were long-necked herbivorous dinosaurs, which include well-known species like Apatosaurus. On the other side of the Saurischian branch, we have the Theropoda. This clade is notable for including bipedal predators that eventually gave rise to birds. The evidence for birds' evolution from theropods includes the structure of hip and wrist bones, as well as the presence of the wishbone, or the fusion of the clavicles, among other similarities.
Given the options to choose from for the clades that constitute the Sauropodomorpha, none of the listed combinations are correct, as Sauropodomorpha is a separate clade under the Saurischia and does not include any of the other groups listed in the options directly. There might be some confusion as the Saurischia is one broader group that includes both Sauropodomorpha and Theropoda. Thus, a more suitable answer would be an option listed as 'Saurischia', but this option is not provided in the student's list.