Answer:
The correct options are C and D
Explanation:
First of all, they have to create active customers as portal users and send them notifications. This is because these set of customers were already doing business with them and have opened support cases. It will be very important to then send them email notifications to inform them that they can now solve their issues easily through the Service Cloud portal. Also, it is also important to involve agents that will guide the customers on the portal registrations.