Vervet County Levies a Real Property Tax Based on the Following

Vervet County levies a real property tax based on the following schedule.
Rate $\quad$$\quad$ Assessed value
3% $\quad$$\quad$ $-0- to $250,000
+ 1% $\quad$ $250,001 and above
-Which of the following statements is false?

A)  If Mr. Clem owns real property valued at $112,500, his average tax rate is 3%.
B)  If Ms. Barker owns real property valued at $455,650, her average tax rate is 2.1%.
C)  If Ms. Lumley owns real property valued at $750,000, her marginal tax rate is 1%.
D)  None of the choices are false.