Final answer:
When faced with a patient who refuses treatment but then collapses and goes into sudden cardiac arrest, it is important to prioritize the patient's life and provide emergency care under implied consent.
Step-by-step explanation:
When faced with a patient who refuses treatment but then collapses and goes into sudden cardiac arrest, it is important to prioritize the patient's life above all else. Option B, providing emergency care under implied consent, is the most appropriate response in this situation. Implied consent means that the patient's refusal of treatment is no longer valid when they are unconscious and unable to make decisions for themselves. It is crucial to begin CPR immediately to increase the chances of survival for the patient.