Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $48,800 28,000 Training of machine operators Processing returned products Scrap processing (disposal) 20,100 25,300 Rework 5,100 Preventative maintenance 29,800 Product design 41,300 Warranty work 6,100 Finished goods inspection 23,300 From the provided schedule of activity costs, determine the external failure costs. a. $20,960 b. $26,200 c. $56,600 d. 884,600