Final answer:
In Milgram's studies, disobedience increased except when orders came from an ordinary man; the correct answer is c. the person ordering them to continue was an ordinary man, apparently another volunteer.
Step-by-step explanation:
In the original studies conducted by Stanley Milgram, people were more likely to disobey under certain altered conditions, which showed how obedience to authority could be affected by various factors. One condition where disobedience did not increase was when 'the person ordering them to continue was an ordinary man, apparently another volunteer'. Participants were generally more willing to follow instructions from an authority figure than an ordinary person. Other circumstances that led to increased disobedience included when the victim was in close proximity, when there was disagreement among the experimenters, and when peers refused to continue. Thus, the correct answer is c. the person ordering them to continue was an ordinary man, apparently another volunteer.