Final answer:
The b) rhombencephalon is the primary vesicle of the embryonic nervous system that corresponds to the hindbrain, which includes the pons, cerebellum, and medulla.
Step-by-step explanation:
The primary vesicle of the embryonic nervous system that corresponds to the hindbrain is the rhombencephalon. During early brain development, the neural tube forms three primary vesicles. The prosencephalon develops into the forebrain, the mesencephalon becomes the midbrain, and the rhombencephalon gives rise to the hindbrain. The rhombencephalon further differentiates into structures including the pons, cerebellum, and medulla. It is important to note that while the prosencephalon and mesencephalon further divide into secondary vesicles, the rhombencephalon goes on to develop without forming additional vesicles at the secondary stage.