What important event occurs after the teacher gives the learner the 150 volt shock in Milgram's experiment?
a. The learner stops answering the questions and ceases to make any noise when shocked.
b. The experimenter threatens to make the teacher switch places with the learner if he refuses to continue.
c. The learner states that he refuses to go on and asks to be let out.
d. The teacher is offered an extra $10 if he agrees to continue shocking the learner.