Final answer:
Cardiopulmonary resuscitation (CPR) is the combination of chest compressions and mouth-to-mouth breathing to revive a person whose heart has stopped.
Step-by-step explanation:
The correct answer is B. Cardiopulmonary resuscitation (CPR). CPR is a life-saving technique used to revive a person whose heart has stopped. It involves combining chest compressions, which circulate blood, and mouth-to-mouth breathing, which supplies oxygen to the lungs. When performing CPR, it is important to place the flat portion of one hand on the sternum and perform chest compressions at a rate of 100 compressions per minute.