Which feature should be used to accomplish this?

Northern Trail Outfitters uses a custom object to track travel requests. Rangers want to have automatic posts on a record whenever a travel request has been approved.

Which feature should be used to accomplish this?
A . Auto-response rule
B . Workflow rule
C . Feed tracking
D . Feed quick action

Answer: C

Explanation:

To have automatic posts on a record whenever a travel request has been approved, feed tracking should be used. Feed tracking enables field updates to be displayed in the Chatter feed of a record or a user profile. Users can follow records or users to see updates in their own feed. Feed tracking can be enabled for standard or custom objects and selected fields.