Schedule of Activity Costs Quality Control Activities Activity Cost Process audits $48,000 Training of machine operators 29,300 Processing returned products 16,000 Scrap processing (disposal) 25,200 Rework 5,100 Preventative maintenance 28,400 Product design 40,900 Warranty work 6,400 Finished goods inspection 23,100 From the provided schedule of activity costs, determine the internal failure costs. Oa. $52,700 Ob. 593,600 Oc. $24,240 Od. $30,300