Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $48,200 Training of machine operators 26,800 Processing returned products 20,200 Scrap processing (disposal) 26,000 Rework 7,100 Preventative maintenance 32,000 Product design 41,000 Warranty work Finished goods inspection 6,200 23,600 From the above schedule of activity costs, determine the non-value-added costs. Oa. $53,300 Ob. $117,900 Oc. $59,500 Od. $231,100