Problem: Kevin sold property with an adjusted basis of $58,000. The buyer assumed Kevin's existing mortgage of $40,000 and agreed to pay an additional $60,000 consisting of a cash down payment of $40,000, and payments of $4,000, plus interest, per year for the next 5 years. Kevin paid selling expenses totaling $2,000. What is Kevin's gross profit percentage?
A. 33.33%
B. 40%
C. 60%
D. 66.67%