CPR Chest Compressions: Proper Hand Placement for Effective Rescue

The correct answer is the heel of one hand.

For effective chest compressions during CPR (Cardiopulmonary Resuscitation), the heel of one hand should be placed on the centre of the person's chest, between the nipples. The other hand should be placed on top of the first hand, interlacing the fingers and keeping them off the person's chest. This method ensures proper placement and adequate force for effective compressions.