You are reviewing the design of a customer dimension table in an existing data warehouse hosted on SQL Azure. The current dimension design does not allow the retention of historical changes to customer attributes such as Postcode. You need to redesign the dimension to enable the full historical reporting of changes to multiple customer attributes including Postcode. What should you do?
A. Add StartDate and EndDate columns to the customer dimension.
B. Add an IsCurrent column to the customer dimension.
C. Enable Snapshot Isolation on the data warehouse.
D. Add CurrentValue and PreviousValue columns to the customer dimension.