Jurisdiction M Imposes an Individual Income Tax Based on the Following

Jurisdiction M imposes an individual income tax based on the following schedule.
Rate $\quad$$\quad$$\quad$ Income bracket
5% $\quad$$\quad$$\quad$$\quad$ $-0- to $50,000
+ 8% $\quad$$\quad$$\quad$ $50,001 to $200,000
+ 12% $\quad$$\quad$$\quad$ $200,001 and above
-Which of the following statements is false?

A)  If Ms. Lui's taxable income is $33,400, her average tax rate is 5%.
B)  If Mr. Bell's taxable income is $519,900, his marginal tax rate is 12%.
C)  If Ms. Vern's taxable income is $188,000, her average tax rate is 7.2%.
D)  None of the choices are false.