Final answer:
The National Highway Traffic Safety Administration (NHTSA) provided federal funding for EMS system development, focusing on improving pre-hospital emergency care related to highway safety.
Step-by-step explanation:
The federal funding for EMS system development was provided by the National Highway Traffic Safety Administration (NHTSA). This federal agency is part of the Department of Transportation and was responsible for initiatives to improve pre-hospital emergency care, which arose due to the highway safety concerns. In contrast, agencies such as the Federal Emergency Management Agency (FEMA), the Social Security Administration, and Medicare serve different functions and were not the primary agencies for providing funding for EMS system development.