Final answer:
CMS is not a private insurance carrier option (4); it's a federal agency that administers healthcare programs like Medicare and Medicaid. The Affordable Care Act aims to provide affordable insurance, and Medicare insures primarily those over sixty-five and some younger disabled individuals.
Step-by-step explanation:
The CMS (Centers for Medicare & Medicaid Services) is the correct answer to the question of which option listed is not a private insurance carrier. Unlike Cigna, Aetna, and United Healthcare, CMS is a federal agency within the United States Department of Health and Human Services (HHS) that administers the nation's major healthcare programs like Medicare and partners with state governments to administer Medicaid.
The goal of the Patient Protection and Affordable Care Act (Obamacare) is to provide all Americans with access to affordable health insurance. Additionally, Medicare is described as the public healthcare system that offers insurance primarily to people over sixty-five years old, although it also covers certain younger people with disabilities.
Medicaid, however, is an insurance program jointly funded by states and the US government that serves poor and/or disabled individuals under the age of 65.