Sally Is a Single Individual Which of the Following Statements Concerning Sally's Tax Rates Is

Sally is a single individual. In 2018, she receives $20,000 of tax-exempt income in addition to her salary and other investment income of $100,000. Sally's 2018 tax return showed the following information:
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$$\begin{array} { l r } \text { Gross income } & \$ 100,000 \\\text { Deductions for adjusted gross income } & ( 4,000 ) \\\text { Adjusted gross income } & \$ 96,000 \\\text { Itemized deductions } & \$ ( 16,000 ) \\\text { Taxable income } & \$ 80,000 \\\text { Total tax } & \$ 13,540 \\\text { Less: Income tax withheld from wages } & ( 13,590 ) \\\text { Refund } & \$ 50\end{array}$$
Which of the following statements concerning Sally's tax rates is (are) correct?
I.Sally's average tax rate is 16.9%.
II.Sally's average tax rate is 13.5%.
III.Sally's marginal tax rate is 22%.
IV.Sally's marginal tax rate is 16.9%.
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A) Statements I and III are correct.
B) Statements I and IV are correct.
C) Statements II and III are correct.
D) Statements II and IV are correct.
E) Only statement IV is correct.