Which part of the tooth does a cusp form?

A cusp is an elevated point or projection found on the occlusal (biting) surface of posterior teeth, such as molars and premolars. These structures are characterized by their pointed projections that help in the efficient grinding and tearing of food during mastication.

Focusing on the correct choice, the elevated points on molars are where cusps are specifically located. Molars typically have multiple cusps due to their complex occlusal surfaces designed for grinding food.

Other parts of the tooth, such as the incisal edge of canines, do not form cusps; instead, the incisal edge is a straight or slightly angled edge that aids in cutting food. The outer surface of the enamel is the protective layer of the tooth and does not pertain to the formation of cusps. The apex of the root refers to the tip of the tooth root, which is involved in anchoring the tooth to the jawbone but does not have any relation to the prominent elevations known as cusps. Understanding these distinctions clarifies why elevated points on molars is the accurate identification of a cusp.