Basic life support (BLS) is defined as:
A. any form of emergency medical treatment that is performed by advanced EMTs, paramedics, physicians, and emergency nurses.
B. basic lifesaving treatment that is performed by bystanders while EMS providers are en route to the scene of an emergency.
C. noninvasive emergency care that is used to treat conditions such as airway obstruction, respiratory arrest, and cardiac arrest.
D. invasive emergency medical interventions such as intravenous therapy, manual defibrillation, and advanced airway management.