The correct answers are A. Streams and D. Out of Office.

Streams allow users to combine multiple Chatter feeds into one custom feed, making it easier to monitor updates from important people, records, and groups. This directly solves the issue of gathering feed updates from core team members. Salesforce documentation describes Chatter streams as custom feeds created by combining multiple related feeds into one feed.

Out of Office helps team members understand who is available to respond. Salesforce documentation explains that users can schedule and customize an out-of-office message and display it next to their name in Chatter.

Why the other options are incorrect:

Topics help categorize Chatter content but do not directly gather core-team feeds or show availability.

Polls are useful for collecting opinions, but they do not solve feed monitoring or availability visibility.

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