Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $52,000 Training of machine operators 27,300 Processing returned products 15,300 Scrap processing (disposal) 25,100 Rework 8,500 Preventative maintenance 31,000 Product design 45,600 Warranty work 9,400 Finished goods inspection 22,700 From the above schedule of activity costs, determine the non-value-added cost Oa. $236,900 Ob. $58,300 Oc. $117,200 Od. $48,900