You are presented with the question "How do dogs conserve body heat?" and the following answer choices: 
- their blood cells
 - fur and fat
 - their nails
 - layers of fat
 - Exfoliation
 - sweating
 - their fur
 - their hair

Now knowing that mammals conserve body heat with their hair or fur and dogs, of course, are mammals, choose the best answer.


 

       their fur  