A new Marketing Cloud (MC) customer wants to now implement a Sales Cloud instance to go along with their MC Instance. The MC instance has been live for a year now, where the primary key for records has been the Email Address.
Which two options would prevent the customer from duplicating records? (Choose 2 answers)

Northern Trail Outfitters wants to send a weekly coupon campaign. They segment their audience using data from several data extensions, which results in an audience size of approximately 200,000 subscribers. They want to send a reminder three days later at the subscribers' optimized send time.
What solution should they use?

A customer needs to compare the engagement across three creative versions, and then send a follow-up email for those contacts who did not engage with any of the test versions.
Which sequence of activities would best accomplish this?

Northern Trail Outfitters wants to integrate Marketing Cloud with its existing point-of-sale system in order in email purchase receipt to its customers. The point-of-sale data will need to be transformed to be received by the Marketing Cloud triggered send API.
What extension product should be used to accomplish this integration?

Northern Trail Outfitters uses separate Marketing Cloud accounts as environments for development, UAT, and production. They want to test all automations and Journeys In each environment prior to launching in production.
Which extension product should be used to speed up the migration of data extensions and Journey Builder configurations between each environment?