What storage model should be used if a subscriber has more than one value for an attribute?

What does Marketing Cloud authenticate when a user logs in through the user interface?

Northern Trail Outfitters wants to drive additional online sales. They are interested in using Einstein to recommend similar items to customers during the checkout process.
Which two terms would they add to their website to accomplish this?
Choose 2 answers

Northern Trail Outfitters wants to segment audiences based on Sales Cloud data.
Where would their Marketing Cloud admin configure Sales Cloud Objects to be synced and leveraged in Marketing Co.

During discovery, the customer outlines data requirements and the anticipated use of Marketing Cloud with the following criteria:
* Customer data will be fully refreshed every night via Import activity from the customer's data warehouse.
* Contact records will be augmented by relational data tables via Contact Builder.
* The customer data file will contain 5M records with 40+ attributes.
* One attribute will house HTML code, 1000 characters max, that will be used to populate Account Access content areas in emails.
* A customer ID will be used as the unique identifier for each contact.
Which statement differentiates the use of data extensions over lists?