Quinn is writing a report on the Affordable Care Act. What is the MOST appropriate subtitle for this report?

• How Americans Overhauled Their Healthcare System
• Why All Americans Get a Subsidy to Pay for Health Insurance
• Why Americans Have the Longest Life Expectancy
• How All Americans Got Access to High-Quality Care

The most appropriate subtitle for Quinn's report on the Affordable Care Act would be "How Americans Overhauled Their Healthcare System." This subtitle accurately describes the main focus of the report, which is to explain the changes and impact of the Affordable Care Act on the American healthcare system. To arrive at this conclusion, we can analyze the other subtitle options:

1. "Why All Americans Get a Subsidy to Pay for Health Insurance" focuses on one aspect of the Affordable Care Act, which is the provision of subsidies, but it does not cover the broader scope of the Act itself.

2. "Why Americans Have the Longest Life Expectancy" does not directly relate to the Affordable Care Act. While the Act may have potentially contributed to improvements in healthcare access and quality, it is not the sole determinant of life expectancy.

3. "How All Americans Got Access to High-Quality Care" also closely relates to the Affordable Care Act, but it does not fully encapsulate the comprehensive overhaul and changes brought about by the Act.

Therefore, "How Americans Overhauled Their Healthcare System" is the most appropriate subtitle for Quinn's report as it effectively summarizes the main focus and content of the report.