Northern Trail Outfitters (NTO) uses a numeric identifier for Subscriber Key. Customer data is stored in a data extension with the Subscriber Key set as a Primary Key.
Which step is required for NTO when creating relationships for this data extension in Data Designer'

A new record is appended to the Orders data extension each time a customer makes a purchase. Which SQL statement would select a unique list of subscribers who have made multiple purchases?

Certification Aid created following AMPscript code: %%[ SET @var1 = 10 SET @var2 = 20 SET @var3 =
30 ]%% How can the three variables be summed up to evaluate to 60? Choose 1.

Certification Aid wants to update Contact data stored in a Data Extension using the REST API. What is required to achieve this? Choose 1.

A developer wants to implement a newsletter registration from on NTO's website. Prior to form submission, an email address provided by the visitor should be validated. Which option could be used to support this scenario?