You are presented with the question "If most reptiles have bad eyesight, the ability to smell is what?" and the following answer choices: 
- dangerous
 - lowered
 - improve
 - positive
 - smelled
 - decreased
 - heightened
 - critical organs

Now knowing that most reptiles have good eyesight and a keen sense of smell and if someone has bad eyesight,the sense of smell is heightened, choose the best answer.


 

       heightened  