Final answer:
The Federal Government's use of net income versus taxable income ensures a progressive tax system, where higher-income individuals pay a larger share of their income in taxes.
Step-by-step explanation:
The Federal Government's use of net income versus taxable income is essential in ensuring a progressive tax system. This system, which is used in the United States, demands higher-income individuals to pay a greater percentage of their incomes in taxes compared to those with lower incomes. This approach aligns with the ability-to-pay principle, which stipulates that individuals who are more capable of bearing the tax burden should contribute a larger share. Conversely, a regressive tax system would require low-income earners to pay a higher percentage of their income in taxes than high-income earners, which is not the case with progressive taxation. Therefore, the correct answer to the student's question would be: The Federal Government's use of net income versus taxable income ensures a progressive tax system.