Mort is the owner of an apartment building containing 10 identical apartments. Mort resides in one apartment and rents out the remaining units. For 2021 the following information is available:Gross rents $ 21,600; Total utilities 2,500; Maintenance/repairs for rental apartments only 1,200; Advertising for vacant apartments 300; Depreciation of building 5,000. What amount should Mort report as rental income for 2021? Question options: a) $ 13,500 b) None of the above c) $ 12,600 d) $ 13,350 e) $ 17,600