Customer B will have a higher service level because, based on the company’s prioritization and the available stock, customer orders are filled in the sequence of customers A, B, and then C. For Item 393, all customer orders are met from the existing stock. For Item 966, there's enough stock to fulfill customer A and B orders completely, but not customer C’s. For Item 769, after fulfilling customer A’s order, there are only 3 items left, which isn't sufficient to meet the orders of either customers B or C in full. Therefore, in cases where stock runs out, customer B’s order is prioritized and more likely to be partially fulfilled compared to customer C.