Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $48,900 Training of machine operators 25,900 Processing returned products 17,200 Scrap processing (disposal) 25,200 Rework 8,200 Preventative maintenance 31,100 Product design 42,300 Warranty work 8,800 Finished goods inspection 23,300 From the provided schedule of activity costs, determine the appraisal costs. Oa. $48,900 Ob. $171,500 Oc. $72,200 Od. $114,600