A Subject in an Experiment on Prejudice Toward the Physically

A subject in an experiment on prejudice toward the physically handicapped is asked by the experimenter to be honest and follow instructions scrupulously-in other words, to adopt the role of "faithful subject." This implies that

A) the experimenter knew the subject was prejudiced toward people with handicaps.
B) the experimenter was trying to minimize the effect of demand characteristics.
C) the experimenter was trying to reduce experimenter bias.
D) "role" was the independent variable in this experiment.