The United States uses a progressive income tax structure, meaning?

The progressive income tax structure in the United States is designed to ensure that individuals who earn more income are taxed at higher rates compared to those with lower incomes. This means that as a taxpayer's income increases, not only do they pay more in total taxes, but a larger percentage of their income is taken as tax.

For example, individuals in lower income brackets might pay a lower tax rate, while those in higher brackets face an increased rate. This system reflects the principle of equity, where the tax burden is distributed based on the taxpayer's ability to pay. Thus, option A accurately represents the essence of a progressive tax system, focusing on the relationship between income level and tax rate.

In contrast, the other choices either misrepresent how taxes are levied in a progressive system, such as suggesting everyone pays the same tax rate or implying that lower earners pay higher rates, which fundamentally misunderstands the intention behind the progressive taxation model.