Corbin reported adjusted gross income of $170,000. Other information is as follows.
Standard deduction..............................................$ 6,300
Personal exemption.................................................4,000
Property and local taxes paid......................................5,000
Business expenses subject to the 2% AGI threshold.........10,000
What amount is added back to taxable income as an adjustment in the calculation of Corbin's alternative minimum taxable income?
a. $21,900
b. $25,300
c. $15,300
d. $17,900