If Susan's Income Increases from $40,000 to $50,000 and Her

Multiple Choice

If Susan's income increases from $40,000 to $50,000 and her tax liability increases from $6,000 to $9,000, which of the following is true?

A) Her marginal tax rate is 18 percent in this range.
B) Her marginal tax rate is 30 percent in this range.
C) Her average tax rate was 22.5 percent when her income was $40,000.
D) The tax structure must be regressive in the range between $40,000 and $50,000.