How do you use the test realm after deployment?

During deployment, you use the customer’s test realm to build the initial configuration.

How do you use the test realm after deployment?
A . Perform all updates in the production realm
B . Validate user master data in the test realm
C . Publish a template in the test realm to automatically update the production realm template
D . Apply changes to templates in the test realm first and then export/import the templates to the production realm

Answer: D