Which of the following best illustrates a progressive tax system?

All taxpayers pay the same percentage of their income in taxes, with those who have higher incomes paying more in taxes.

Taxpayers pay taxes based on income brackets, with the percentage of taxes paid on income increasing as the taxpayer moves to a higher bracket.

Taxpayers pay a flat percentage tax based on the total value of their real estate holdings.

Taxpayers pay a flat percentage tax on sales, so that those who spend more pay more in taxes.