Question

which of the following is not found in all molluscs? visceral mass muscular foot mantle radula

Explanation:

Molluscs have a basic body - plan that includes a visceral mass (containing internal organs), a muscular foot (used for locomotion), and a mantle (which may secrete a shell). However, the radula, a feeding structure with teeth - like projections, is not present in all molluscs. For example, bivalves (such as clams and oysters) lack a radula.

Answer:

radula