You are presented with the question "What differ strongly in appearance and are barrel shaped?" and the following answer choices: 
- bears
 - barnacles
 - abdomens
 - oxen
 - Leptospirosis
 - cacti
 - burrs
 - tunicates

Now knowing that adult tunicates are barrel-shaped and tunicates differ strongly in appearance between the adult and larva, choose the best answer.


 

        tunicates 