A complete inventory listing is printed only once a year. Errors in the perpetual inventory records may remain undetected for too long a time period. Select one: a. Inventory listings should be printed periodically throughout the year, and physical counts compared to the listing on a cycle basis. b. Have the system check inventory availability as order data are entered; if the customer is on the phone at this time, inventory availability may be confirmed directly to the customer. c. Maintain an online master file for customer account and credit data in addition to inventory data. d. Use online terminals to enter sales order data into the system as orders are received