This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
When you come across an unresponsive patient, the next step is: 
Select and explain. 
A. Shout and shake the patient, B. Check for carotid pulsations, C. Secure the airway, D. Start chest compressions
B: Check for carotid pulsations
Answer: B: Check for carotid pulsations 
Explanation: Shouting and shaking is checking for responsiveness: The patient is already described as unresponsive, i.e., not responding to shouts or shakes.
The next step in an unresponsive patient is to check for carotid pulsations; if not palpable, consider that the patient is in cardio-respiratory arrest and immediately initiate CPR.
CPR is initiated as Circulation -> Airway -> Breathing (CAB), not ABC any longer.