Exam Certified Platform App Builder topic 1 question 224 discussion

B "Unlisted: Only group members and users with the “Manage Unlisted Groups” permission can see and add posts, comments, and files. People can’t ask to join the group. The group’s owner or managers must invite the group members. Unlisted groups offer more privacy and nonmembers can’t see or access unlisted groups in list views, feeds, or search results." https://help.salesforce.com/s/articleView?id=sf.collab_group_about.htm&language=en_US&release=240.17.0&type=5

B is correct Only members of the group (note that people with special privileges, like "Manage Unlisted Groups" or "Modify Unlisted Groups," can also see the mentioned post). Unlisted is most restrictive.