Which of the Following Would Indicate That a Tax Is

Which of the following would indicate that a tax is regressive?

A) High-income earners pay $5,000 in taxes; low-income earners pay $2,000 in taxes.
B) Both high-income and low-income earners pay $200 each in taxes.
C) High-income earners pay 20 percent of their income in taxes; low-income earners pay 10 percent of their income in taxes.
D) Both high-income and low-income earners pay 10 percent of their income in taxes.
E) Low-income earners are exempt from taxes.