Northern Trail Outfitters has a contact count of nearly 10 million records.

Comprehensive and Detailed Explanation:

The correct answers are A and C.

A — Performing large segmentation in Automation Studio reduces the processing load inside Journey Builder, helping Journeys to focus only on eligible contacts.

C — Storing decision split data in Contact Builder’s Attribute Groups allows journeys to reference Contact Data instead of relying on static Journey Data, enabling faster and dynamic splits.

❌ Why others are wrong:

B: Applying filters inside the Journey can slow down entry and cause processing delays.

D: Creating multiple copies of DEs can cause unnecessary data duplication and still doesn't solve processing speed.

Exact Extract from Salesforce Official Documentation:

Salesforce Help — Journey Performance Best Practices:

"Optimize journey performance by filtering contacts prior to journey entry and by using Contact Data for decision splits rather than static Journey Data."

(Source: https://help.salesforce.com/s/articleView?id=sf.mc_jb_best_practices.htm )

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