Which One of the Following Statements Is Correct

Which one of the following statements is correct?

A) An aging schedule helps identify which customers are the most delinquent.
B) The percentage of total receivables that fall within a certain time period on an aging schedule will remain constant over time even if the firm has seasonal sales.
C) Normally firms call their delinquent customers prior to sending them a past due letter.
D) A constant average collection period over a period of time is cause for concern.
E) It is common practice when a customer files bankruptcy to sell that customer's receivable at face value.