You are presented with the question "What are the structural and functional units of the organ that filters blood?" and the following answer choices: 
- lungs
 - nephrons
 - humans
 - pancreas
 - eardrum
 - alveoli
 - epidermal
 - organ

Now knowing that nephrons are the structural and functional units of the kidneys and blood is filtered in the kidney, choose the best answer.


 

  nephrons       