Carroll, a 35 year old unmarried taxpayer with an adjusted gross income of $100,000, incurred and paid the following unreimbursed medical expenses for the year: Doctor bills resulting from a serious fall $ 5,000 Cosmetic surgery that was necessary to correct a congenital deformity 15,000 Carroll had no medical insurance. For regular income tax purposes, what was Carroll's maximum allowable medical expense deduction, after the applicable threshold limitation, for the year? a. $20,000 b. $0 c. $15,000 d. $10,000