Jenkins transferred land worth $50,000 to his controlled corporation for stock of the corporation worth $20,000 and cash of $20,000. The basis of the property to him was $15,000 and was subject to a $10,000 mortgage (non-bona fide business purpose), which the corporation assumed. Jenkins must report a gain of how much? 

A. $10,000 

B. $20,000 

C. $30,000 

D. $35,000