Which Statement Best Describes an Aspect of Stanley Milgram's Study

Which statement best describes an aspect of Stanley Milgram's study of obedience?

A) an ominous-looking shock machine had voltage markings from zero to 450 volts
B) participants in the study were randomly assigned to be teachers or learners
C) participants were shocked when they made errors in reciting word pairs
D) a learner and the teacher sat side by side across from the shock machine