START (Simple Triage and Rapid Treatment) is a triage method taught by the National Registry of Emergency Medical Technicians for use in mass-casualty incidents. START allows rescuers to quickly prioritize patients based on the severity of their conditions using objective criteria that can be assessed in under 60 seconds.

The correct components of the START system are Respirations, Perfusion, and Mental Status (RPM), making Option D correct. EMTs first assess whether the patient is breathing and evaluate respiratory rate. Next, perfusion is assessed by checking radial pulse or capillary refill. Finally, mental status is evaluated by determining whether the patient can follow simple commands.

Option A describes elements of a general patient assessment, not START triage.

Option B refers to the primary assessment sequence, not mass-casualty triage.

Option C lists triage categories rather than assessment components.

NREMT emphasizes START triage as a rapid, standardized approach to manage large numbers of patients efficiently while maximizing survivability.