The Affordable Care Act requires that most U$.$S$.$ citizens and legal residents have qualifying health insurance or pay a financial penalty. Despite the fact that a subsequent law has since removed the enforcement of this penalty, requirement to have health insurance still exists. This provision of the Affordable Care Act is known as the

a$)$ individual mandate.

b$)$ premium subsidy option.

c$)$ public option.

d$)$ Health Insurance Marketplace option.