Donna files as a head of household in 2010 and has taxable income of $90,000, including the sale of a stock held as an investment for two years at a gain of $20,000. Only one asset was sold during the year and Donna does not have any capital loss carryovers. What is the amount of Donnas tax liability?

A. 13,750

B. 15,347

C. 17,347.50

D. 18,750