Final answer:
The shape of the cranial vault is ovoid, accommodating the shape of the brain, while the facial bones form the face and cavities for sensory organs. Facial prognathism varies and cannot be determined without further context.
Step-by-step explanation:
The shape of the cranial vault is generally ovoid, designed to accommodate the shape of the brain. The cranial vault includes the frontal, parietal, and sphenoid bones which cover the top of the head. Meanwhile, the facial bones of the skull, though not specified in the provided information, typically exhibit a degree of facial prognathism depending on the species and individual genetic factors. Facial prognathism is the degree to which the face protrudes in relation to the cranial base and this varies widely across human populations.
The facial bones form the structures of the face, enclosing cavities for the eyes, nose, and mouth. Therefore, in describing the shape of the cranial vault and face and the presence of facial prognathism, the correct answer to the student's question would be ovoid (d), although facial prognathism cannot be exactly determined without additional context regarding the specific skull in question.