You are presented with the question "What are some invertebrates protected by on their backs?" and the following answer choices: 
- fur
 - parasites
 - barnacles
 - shells
 - coats
 - bones
 - bushes
 - Epidermis

Now knowing that mollusks are invertebrates such as the common snail and snails are protected by a hard shell on their backs, choose the best answer.


 

    shells     