You are presented with the quiz "Damage to the structural units of the kidneys can be caused by  .." 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "nephrons are the structural and functional units of the kidneys" and "damage to the nephrons can be caused by conditions such as diabetes and high blood pressure ". 

So, what's the best answer to the question?


 

        high blood pressure   