The Nurse Is Teaching Cardiopulmonary Resuscitation (CPR) to a Group

The nurse is teaching cardiopulmonary resuscitation (CPR) to a group of lay persons. Which of the following behaviors by one of the participants would indicate the need for further review?

A) Letting the fingers rest on the chest
B) Keeping the shoulders directly over the hands
C) Straightening the arms and locking the elbows
D) Placing the heel of the hand over the lower half of the sternum