What Is the "Free Rider Problem" in Healthcare

What is the "free rider problem" in healthcare?

A) The poor do not pay for their healthcare, but instead rely on the requirement that hospitals stabilize everyone who comes to an emergency room with a medical problem.
B) The poor use emergency rooms as their primary care providers, and that is more costly than other ways of securing medical care.
C) Hospitals are not allowed to charge people below the poverty line for ambulance services, so these are overused.
D) Young people do not get insurance until later in life when they are more likely to get sick or injured, and take advantage of the premiums paid by others who have been in the system all along.