The nontaxonomic term sea slug encompasses a wide variety of marine gastropods. One feature they share as adults is the lack of a shell. We might think, therefore, that they represent defenseless morsels for predators. In fact, sea slugs have multiple defenses. Some sea slugs prey on sponges and concentrate sponge toxins in their tissues. Others feed on cnidarians, digesting everything except the nematocysts, which they then transfer to their own skins. Whereas the most brightly colored sea slugs are often highly toxic, others are nontoxic and mimic the coloration of the toxic species. Their colors are mostly derived from pigments in their prey. There are also sea slugs that use their coloration to blend into their environments. a.nematocystsb. an incurrent siphonc. a radulad. a mantle cavity

Option D, A radula

Explanation:

Complete question

Which structure do sea slugs use to feed on their prey?

A) nematocysts

B) a sharp beak

C) an incurrent siphon

D) a radula

E) a mantle cavity

Solution

Sea slung are known as marine gastropod mollusks and like all other member of the mollusk family, sea slug uses their radula to capture their food.  

A radula is basically a chitinous ribbion which is used for holding, cutting and chewing food.  

Most of the gastropod mollusks feed on diatoms by grazing and scraping them through radula.  

Hence, option D is correct

the trilobite is used as an index fossil for various geologic time periods as specific types of the trilobites were present in different geological time periods. they are a group of marine arthropods belonging to the class of trilobita.

explanation:

i think the answer is b.

hope it