Zephex is a calendar year corporation. On December 1, 2015, Zephex received a $12,000 check from a tenant that leases office space owned by Zephex. This payment was rent for the four-month period from December 1, 2015, through March 31, 2016. On December 2, 2015, Zephex billed a client $38,250 for services rendered to the client in November. The client did not pay the bill until January 14, 2016. a. If Zephex is a cash basis taxpayer, how much 2015 income should it recognize with respect to the above transactions?