You are presented with the question "Neurons are the structural and functional units of where what is critical?" and the following answer choices: 
- organs
 - Glial cells
 - nerves
 - Structural units
 - voltage
 - Storage units
 - Critical care
 - A computer

Now knowing that neurons are the structural and functional units of the nervous system and glial cells perform critical functions in the nervous system, choose the best answer.


 

  Glial cells       