In the context of an invoice customer sub-type entity, if the billing address is the same as the delivery address in the parent customer entity, which of the following statements is correct?
a) The billing and delivery addresses should always be different for proper record-keeping.
b) It is a common practice to have the billing address match the delivery address for streamlined transactions.
c) The billing address is not relevant in the context of an invoice customer sub-type entity.
d) The delivery address is irrelevant when considering the billing process in the parent customer entity.
