Which of the following statements is a criterion for selecting behaviors and actions for customer-defined service standards?
选项：

A:Customer-defined standards should be based on behaviors and actions that are very important to customers
B:Customer-defined standards should be challenging even if that means they are unrealistic
C:Customer-defined standards should be reactive rather than predictive
D:Customer-defined standards should be established for behaviors and actions that at the present time cannot be improved
E:All of the above are criteria for selecting behaviors and actions for customer-defined service standards