Time left 0:44:0 Which one the following procedures performed for the billing function provides evidence for the existence assertion? Select one: O a. Making sure that each shipment is billed to the proper customer Ob. Making sure that all billings have been shipped. Oc Making sure that no shipment has been billed more than twice. od Making sure that each shipment is billed at the correct amount, e. Making sure that all shipments have been billed. Next page