UofM provides free pizza to its employees every Friday, which is delivered by Dominos. Every month, Dominos sends UofM an invoice for the Friday pizza deliveries. This arrangement is best described as a blanket purchase order. set purchase order O standard purchase order fixed purchase order The possibility that auditors will fail to uncover material errors even though the auditors are following audit procedures and using good judgment is referred to as control risk. detection risk. investigating risk. inherent risk