Fact 1: Echinoderms lack respiratory and excretory systems.

Fact 2: Starfish and sea urchins are also echinoderms.

Given the two facts above, answer the question "what lack respiratory and excretory systems?" with the following options: 
- fish
 - graptolites
 - starfish
 - waste
 - humans
 - barnacles
 - insects
 - ferns


 

   starfish      