A 30-year-old man is brought to the emergency department after a high-speed road traffic collision. He is unresponsive. According to the ABCDE approach, what is the most appropriate first step in assessing and managing this patient?ACheck blood pressure and start intravenous fluidsBExpose the patient fully to look for injuriesCAssess and secure the airway with cervical spine protectionDPerform a full neurological examinationETake a detailed history from the ambulance crew before any interventionsCheck my answer