You are about to be given electric shock

You have agreed to participate in an experiment, where you are being paid. In this situation, there are four roles i.e. instructor, evaluator, tester, and punisher. Tester is given multiple choice questions and he has to choose the correct answer. Tester, who is seated in next room, needs to say his answer loudly to avoid any wrong evaluation.

In case of a wrong answer, the evaluator confirms to instructor, who instructs punisher to administer electric shock. The intensity of shock increases with each wrong answer and becomes unbearable.

You have agreed to play the role of punisher. In the last round, when you administered the electric shock, you could hear tester's painful sounds and his requests to stop the shocks. In the next round, you have to administer higher intensity shock, which can be harmful.

In the next round, the tester has again chosen the wrong answer. The instructor advises you to administer the higher intensity shock to the tester.

What will you do?