B. Second Arch 1. During development, the thymus will descend caudally pulling parathyroid 3 with it, thus parathyroid 3 will ultimately rest inferior to parathyroid 4. C. Third Arch 1. Arch forms greater cornu of hyoid, and part of the body along with the stylopharyngeus m. 2. Nerve is the glossopharyngeal.
Artery is the precursor of the carotid artery on both sides.
Pouch forms the thymus and parathyroid 4. D. Fourth Arch 1. Arch forms the thyroid cartilage, cuneiform cartilage. Nerve is the superior laryngeal N. 3. The left 4th arch artery becomes the arch of the aorta.