Dr. Eugene Nagel advanced emergency medical treatment in 1969 by:

A) training paramedics to administer certain medications directly through the chest wall and into the left ventricle.
B) developing and implementing closed-chest cardiac massage (CPR) in order to pump blood in a patient without a pulse.
C) implementing the "golden hour," which dramatically increased survival rates of patients who experienced severe trauma.
D) developing a telemetry system that enabled fire fighters to transmit a patient's electrocardiogram to the physician at the hospital.

Answer: D) developing a telemetry system that enabled fire fighters to transmit a patient's electrocardiogram to the physician at the hospital.