You are presented with the question "Adult spiny skinned animals found only in marine environments have what?" and the following answer choices: 
- sensory neurons
 - to stay warm
 - Animal survival
 - extra brains
 - aerobic capacity
 - eight eyes
 - asymmetrical axis
 - radial symmetry

Now knowing that adult echinoderms have radial symmetry and echinoderms are spiny skinned animals found only in marine environments, choose the best answer.


 

        radial symmetry 