Which of the following is not an example or illustration of the adverse selection problem (a.k.a. the problem of hidden information) of third-party payers?

People buy health insurance to cover and protect themselves in case they might someday need it to cover big medical expenses.

All of the choices listed here

Sicker people buy more health insurance coverage or more robust health plans, while healthier people buy less coverage.

Anticipating they will require some surgical and other costly procedures soon, people who already have health insurance decide to switch to more generous health insurance plans during next week's open enrollment period.

Some people do not buy health insurance at all, until the time comes when they need it to cover costly medical procedures.