Most grocery stores use bar code scanning technologies that interface with cash registers used to process customer purchases. Cashiers use the scanners to read bar code labels attached to each product, which the system then uses to obtain unit prices, calculate transaction totals, including sales taxes, and update perpetual inventory databases. Similarly, cashiers scan bar codes on coupons or member discount cards presented by the customer to process discounts. Along with the scanning technologies, groceries use point-of-sale technologies that allow customers to swipe debit and credit cards for payment, while still maintaining the ability for customers to pay with cash. Read the requirements. Requirement c. How might an auditor use technology to test the operating effectiveness of a bar code scanner based check-out system? (Select all that apply.) A. The auditor may be able to use audit software to test the accuracy of the postings of daily totals to the client's general ledger system. B. The auditor may use audit software to review all unit prices in the price list master file to identify unusual price amounts for further investigation (e.g., negative prices, large unit prices, etc.) O C. The auditor may be able to use audit software to identify the most recent date of sale by product number to identify those products that have not been sold to customers for an extended period of time to identify potentially obsolete inventory still on hand. D. The auditor could select a number of different products and use the bar scanning technology to process the sales amounts for comparison to the auditor's separate calculation of transaction amounts based on items processed. The auditor could perform the same kind of test using coupons and other discount programs. E. The auditor may be able to use audit software to test the accuracy of individual customer transactions and to test the summation of all customer transactions processed by cash register machine, by day, and by store