What are some of the prerequisites for creation of a credit memo based on a credit memo request? Note: There are 2 correct answers to this question.

What are some of the prerequisites for creation of a credit memo based on a credit memo request? Note: There are 2 correct answers to this question.
A . The billing document of the original customer invoice must be cancelled.
B . An appropriate reason for rejection must be assigned to the original sales order item.
C . Copying control must exist between the sales document and the billing document.
D . The Billing Block field in the credit memo request must be empty.

Answer: B, D