Final answer:
D) Patient care. The first priority as an EMT at the scene of a medical emergency is patient care.
Step-by-step explanation:
As an EMT, your first priority when arriving at the scene of a medical emergency is patient care (D). While patient advocacy (A) is important, providing immediate medical attention to the patient takes precedence.
Personal safety (B) is also important, but it is not the first priority. Ensuring public safety (C) is also important, but again, it is not the immediate concern when you first arrive at the scene.
Upon arrival, you should assess the patient's condition, provide necessary medical intervention, and prioritize their well-being.