You are presented with the question "what adults have radial symmetry?" and the following answer choices: 
- sea urchins
 - graptolites
 - humans
 - fur seals
 - barnacles
 - insects
 - h2o
 - gastropod shells

Now knowing that adult echinoderms have radial symmetry and starfish and sea urchins are also echinoderms, choose the best answer.


 

 sea urchins        