Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $50,800 Training of machine operators 29,800 Processing returned products 18,700 Scrap processing (disposal) 25,300 9,000 Rework Preventative maintenance 30,600 Product design 41,900 Warranty work 9,200 Finished goods inspection 22,800 From the provided schedule of activity costs, determine the value-added costs. a. $153,100 Ob. $238.100 Oc. $185,100 Od. $175,900