C-A-B in basic life support stands for:

The correct understanding of the acronym C-A-B in basic life support is crucial for effective emergency response. The sequence refers to "Chest compressions, Airway, and Breathing."

This approach emphasizes the importance of prioritizing chest compressions when performing cardiopulmonary resuscitation (CPR). Starting with chest compressions helps to circulate blood and maintain blood flow to vital organs, particularly the heart and brain, until more advanced medical help can arrive or the situation is resolved. After initiating chest compressions, it's important to ensure that the airway is clear, followed by administering rescue breaths if needed.

This sequence reflects the latest guidelines that prioritize quick, effective action to increase the chances of survival in cases of cardiac arrest. In contrast, the other options do not accurately reflect this order or focus. For instance, while some may mention aspects of care or calling for help, they do not encompass the critical and immediate steps emphasized in current CPR protocols. Understanding the importance of these specific terms and their order can significantly impact the effectiveness of emergency care provided.