Final answer:
The clade of mollusk that includes fully terrestrial (land dwelling) species is the class Gastropoda.
Step-by-step explanation:
The clade of mollusk that includes fully terrestrial (land dwelling) species is the class Gastropoda.
Gastropods are a large and diverse group of mollusks that includes snails and slugs. While many gastropods are aquatic, all terrestrial mollusks belong to this class.
Examples of terrestrial gastropods include garden snails and slugs, which have adapted to live in various terrestrial habitats.