Final answer:
The Lateral view is best for visualizing the velum and posterior pharyngeal wall, as it directly aligns with the planes of these anatomical structures.
Step-by-step explanation:
The optimal view for visualizing the velum and posterior pharyngeal wall is the Lateral view. The lateral view allows clear observation of the structures of the pharynx, including the laryngopharynx, which is inferior to the oropharynx and posterior to the larynx. The anterior-posterior (AP) view wouldn't show these areas as clearly because of the orientation of the velum and pharyngeal wall. Similarly, oblique and inferior views are less suitable for observing the desired anatomical structures in the pharyngeal region.