Question

which of these is the largest class in phylum mollusca, and includes freshwater, saltwater, and terrestrial organisms with single, spiraled shells? class gastropoda class bivalvia

Explanation:

In Phylum Mollusca, Class Gastropoda is the largest class. Gastropods include organisms (like snails, slugs) with single, spiraled shells (in many species) and are found in freshwater, saltwater, and terrestrial habitats. Class Bivalvia (e.g., clams, oysters) has two shells and is not characterized by single, spiraled shells, nor is it the largest class in Mollusca.

Answer:

A. Class Gastropoda