You are presented with the question "What could not produce enough offspring?" and the following answer choices: 
- Deoxyribonucleicacid
 - killer whales
 - Echinoids
 - single-celled organisms
 - sparrows
 - great white sharks
 - passenger pigeons
 - one celled organisms

Now knowing that if all members of a species cannot produce offspring then that species will likely become extinct and passenger pigeons are extinct, choose the best answer.


 

       passenger pigeons  