You add a lookup for contacts to the case form.

You add a lookup for contacts to the case form.
You need to display the most recent primary phone number for a contact on the case form while minimizing administrative effort What should you do?
A. Use a workflow to copy the phone number to a new field on the case when the contact changes.
B. Use a quick view form to display the phone number.
C. Use a web resource to query and display the phone number.
D. Use field mapping during record creation to copy the phone number to a new field on the case.