Fact 1: Adult echinoderms have radial symmetry.

Fact 2: Sea urchins are echinoderms, in the same family as starfish.

Given the two facts above, answer the question "What has radial symmetry?" with the following options: 
- peachleaf willow
 - sea urchins
 - humans
 - gastropod shells
 - A Greek letter
 - asymmetry
 - dogs
 - Most plants


 

  sea urchins       