B) flexibility , is what will improve due to these activities.
Answer: Rapid defibrillation is the basic step of survival because it abolish the abnormal heart rhythm.
Explanation: When a particular person suffers from a sudden heart/cardiac arrest and it disrupts the heart beat which is known as ventricular fibrillation , then also it is possible for the patient to revive from that situation by rapid defibrillation. Rapid defibrillation is used for the retrieving the normal heart rhythm/beat. Thus is a major factor for the retaining a person's life