What is an X stream?
- A contact list of followers you acquired from X
- A data list of keywords to monitor that appears after uploading a list of your X contacts
- A display of posts that you developed in the social inbox to promote a specific campaign
- A display of posts that match pre-defined, saved searches on specific criteria
Explanation
In HubSpot, this feature is currently documented as X feeds, which are saved searches used to monitor conversations in the social monitoring tool. Posts appear in the feed when they match predefined criteria such as keywords, mentions, reposts, or timeline activity. That means the feature is a monitored display based on saved search conditions rather than a stored audience or publishing asset. The key idea is ongoing social monitoring through search-based results inside HubSpot. HubSpot Knowledge Base+1
Why the other options are incorrect
A) This describes a follower or contact database, but HubSpot defines the feature as a search-based monitoring feed. HubSpot Knowledge Base
B) HubSpot does not define the feature as an uploaded contact list tied to keywords; it is created from saved monitoring criteria. HubSpot Knowledge Base
C) This confuses social monitoring with social inbox or publishing, while the feature is for displaying matched posts from saved searches. HubSpot Knowledge Base+1
Source for verification
https://knowledge.hubspot.com/social/create-and-monitor-twitter-streams
https://knowledge.hubspot.com/social/social-streams