You are presented with the quiz "How long can antibodies protect the body?" 

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 administered to the patient in a process called passive immunization". 

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


 

 As long as antibodies survive          