You are presented with the quiz "passive immunity lasts only as long as what survives in body fluids?" 

But you don't know the answer, so you turn to your teacher to ask for hints. He says that "passive immunity lasts only as long as the antibodies survive in body fluids" and "antibodies are also called gammaglobulins". 

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


 

  gammaglobulins         