Which of the Following Would Indicate That a Tax Is

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

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