Hamid spends an hour studying instead of watching tv with his friends. the opportunity cost to him of studying is

- "ethical issues. deception – the participants actually believed they were shocking a real person and were unaware the learner was a confederate of milgram's. however, milgram argued that “illusion is used when necessary in order to set the stage for the revelation of certain difficult-to-get-at-truths.” "

- "milgram's work was conducted in the early 1960s before the current.the studies ignited a debate about the ethical treatment of participants. what appear to be dangerous, if not deadly, electric shocks and the by today's ethical standards, many questions about the research have gone unanswered."

the answer is d. amendments.