Final answer:
Immediate recognition of cardiac arrest is the most important factor for survival, with administering CPR swiftly being crucial to maintain blood circulation until advanced care arrives (option B).
Step-by-step explanation:
The single most important factor in determining survival from cardiac arrest is B. Immediate recognition. Rapid recognition of cardiac arrest leads to earlier initiation of CPR (cardiopulmonary resuscitation), which is crucial for maintaining vital blood flow to the heart and brain until more advanced life support can be provided. While rapid transport, effective advanced life support (ALS), and early defibrillation are also important, none have as significant an impact on survival as the immediate initiation of CPR, which sustains life by manually pumping blood through the heart when it cannot do so on its own.
Automated external defibrillators (AEDs) are found in many public places and should be used as soon as possible when available, following CPR. They provide spoken instructions and can deliver a shock to the heart to restore normal rhythm, which can be crucial in the case of ventricular fibrillation or pulseless ventricular tachycardia, the most common arrhythmic causes of cardiac arrest.
Hence, the answer is option b.