You are presented with the question "What are used for seeing by animals by sensing light?" and the following answer choices: 
- photons
 - fingers
 - cactuses
 - ears
 - pupils
 - Decibels
 - noses
 - bullfrogs

Now knowing that eyes are used for seeing by animals by sensing light and light enters the eye through the pupil, choose the best answer.


 

     pupils    