How Did the Idea of Health Insurance Come About

How did the idea of health insurance come about?

A) The U.S. followed the European model
B) During WWII, companies could not afford to increase wages so they used health care coverage as a perk for employees
C) Doctors pooled together after the Great Depression to set prices and contract with insurance companies so that they could better protect their practices and focus on caring for patients.
D) Once the government started paying for the health care of the elderly and for low-income families in the 1960s, those companies that coordinated the care for the government began to offer coverage for private employers as well.