Which of the following statements about Subscriber Key is true?

The statement that the Subscriber Key can be populated with a unique identifier is true because the Subscriber Key is designed to uniquely identify a subscriber within Salesforce Marketing Cloud. This key serves as a critical reference point for maintaining subscriber data across different data sources and ensuring accurate tracking and personalization of communications. Utilizing a unique identifier, such as a customer ID or another distinct value, allows marketers to manage audiences more effectively, particularly when dealing with multiple channels or systems. The flexibility of the Subscriber Key in being assigned to different values also enables personalized experiences, targeted campaigns, and refined audience segmentation within the platform.

The other statements do not capture the essence of the Subscriber Key’s primary purpose and functionality. For instance, it does not determine the email template, is essential for audience segmentation, and is not required to be the same as the email address.