You are presented with the question "What defense mechanism does a porcupine use when intimidated?" and the following answer choices: 
- eardrum
 - deadly
 - sound
 - instincts
 - steroids
 - organ
 - quills
 - blastoids

Now knowing that threatening behavior by predators causes a porcupine to extend its quills and similarly, threatening or intimidating behaviors are also forbidden, choose the best answer.


 

       quills  