Comprehensive and Detailed Explanation:

The correct answer is D — Use a Data Extension Entry Source with an applied filter based on recent member activity.

Using a Data Extension Entry Source allows direct filtering based on attributes like “recent activity” at the time of journey configuration.

This method efficiently filters at entry without requiring separate automation processes or manual queries.

❌ Why others are wrong:

A: Import Activity would require manual or scheduled imports; unnecessary here.

B: Query Activity creates additional complexity; Journey Builder filtering is more efficient.

C: Contact Data Entry Source is used when leveraging Attribute Groups, but it’s more complex than necessary for simple recent activity checks.

Exact Extract from Salesforce Official Documentation:

Salesforce Help — Journey Builder Entry Sources:

"A Data Extension Entry Source can include filter criteria to ensure only qualifying contacts enter the journey without requiring pre-segmentation."

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