Which two options should the consultant recommend?

Northern Trail Outfitters recently purchased Marketing Cloud to start running cross-channel campaigns. They are looking for guidance on which value to use as the subscriber key.

Which two options should the consultant recommend? (Choose 2 answers)
A . Email
B. CRM ID
C. Mobile Device ID
D. Loyalty Program Number

Answer: B,D

Explanation:

To choose a subscriber key for Marketing Cloud, Northern Trail Outfitters should use a value that is unique, persistent, and channel-agnostic. A CRM ID or a loyalty program number are both good options, as they meet these criteria and can be used to identify and track subscribers across different channels and platforms. Email and mobile device ID are not good options, as they are not unique or persistent (subscribers can change their email or device) and they are specific to one channel (email or mobile).

References: https://help.salesforce.com/s/articleView?id=sf.mc_co_subscriber_key.htm&type=5