You are presented with the question "Crustaceans and insects have what special structures?" and the following answer choices: 
- the eyes
 - a cuticle
 - internal
 - excretory
 - invisible
 - Chlorophyll
 - fur and fat
 - muscled

Now knowing that some arthropods have special excretory structures and crustaceans are, like insects, arthropods, choose the best answer.


 

    excretory     