A: Almost anything.
OK, this one's a major peeve of mine. Free is one of the most deceptive words in the English language, and should really be retired. We need to find something to replace it with. What "free" means is simply that the person who pays for a product or service and the person who consumes it are two different people. This is the idea that made such a mess of the Soviet bloc. It's the reason NASA once paid nearly a million dollars to transport 3 bolts from Texas to Florida. And it, in large part, is the reason our health care system is broken.
I work for a company that makes health care-related software. Without getting into details that might get me in trouble, the reason our software exists is this: Health care providers' fees are based largely on what they can collect-- from insurance companies, from Medicare (don't get me started...), from state and local governments, etc. And their income is almost completely a function of that same dynamic. This is the origin of "managed care". Insurance companies realized that what they pay out is controlled more by providers than consumers. Managed care is the way they control the providers.
Read that paragraph again. Notice I didn't say a word about how anybody controls costs. Not a word about competitive forces. After all, what need is there to control costs when you can just turn up the "stickler" knob and extract more money from the payer?
The fact that cars aren't "free" is the reason we pay so much less per mile today than we did 20 years ago. The fact that semiconductors aren't free is the reason we have Moore's Law. I've got to wonder to what extent health care is expensive because you consume the services and somebody else pays the bill.