Mark receives a liquidating distribution from Arosa Corporation as part of a redemption of all of its stock. Mark's basis for his Arosa stock is $10,000. In exchange for his stock, Mark receives property with a $10,000 basis and a $25,000 fair market value that is subject to a $12,000 mortgage, and also receives cash of $15,000. What is Mark's recognized gain?
a. $42,000
b. $30,000
c. $18,000
d. $3,000