Ans.
Mollusks are organisms belong to phylum Mollusca. These organisms show presence of unsegmented soft body, presence of an external or internal shell, bilateral symmetry, a tongue-like structure or radula, a mantle (a fold in wall of body that covers the shell), muscular foot, and a fluid-filled cavity or coelom.
Thus, the correct answer is 'radula' and 'mantle'.