Final answer:
(A) sovereign immunity
The protection that government-run EMS services have from lawsuits by those they treat is called sovereign immunity. It is a legal doctrine that prevents states and state entities from being sued without their consent.
Step-by-step explanation:
A type of immunity that protects governmentally run EMS services from being sued by persons they treat is called sovereign immunity. Sovereign immunity is a legal doctrine that makes states immune from lawsuits unless they consent to be sued.
This immunity extends to various forms of government service, including emergency medical services (EMS) which are funded through taxation and provide services without additional charges, as described in the example of a government-funded fire department ambulance.
The concept has its roots in the principles of state sovereignty, which is foundational to international law and provides the framework within which these services operate.