Northern Train Outfitters needs to ensure that "Valued Customer" appears if no data exists in that field for a subscriber when using a personalization string to display the First_Name field in a data extension. How can the Marketer most easily achieve this during creation of the data extension?

Northern Trail Outfitters wants to optimize email engagement.
Which elements could they test using the A/B Test feature?

A 15 person management team wants to review test emails built in email studio prior to live
deployment based on content that is personalized for them but it clearly noted as a test email
what is the safest most effective way for a marketer to accomplish this task without the
compromising email content.

What is a table within the application database that stores sendable subscriber data as well as relational data like
purchases, inventory, rewards programme data?

Northern Trail Outfitters (NTO) stores sales representative information in a data extension. NTO wants to personalize the From Name in emails with the targeted customer's specific representative.
Which functionalities accomplish the requested configuration?