You Are Participating in an Experiment That Requires You to Initially

You are participating in an experiment that requires you to initially release minute amounts of a toxic gas into a chamber where subjects are trying to solve puzzles.However,with every mistake they make,you are instructed to release greater and greater amounts of the gas.What factor would most inhibit your willingness to continue on?

A) Proximity to the subjects
B) Screams and protests from the subjects
C) Being able to actually see the subjects
D) Where the study was taking place