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. b. If Zephex is an accrual basis taxpayer, how much 2015 book income should it report and how much 2015 taxable income should it recognize with respect to the above transactions