What are the three different custom tabs you can create? (Choose three.)

Universal Containers would like to collaborate with its customers within Salesforce, and has decided to enable the "Allow Customer Invitations" Chatter Setting.
What permission is granted to Customers when invited to a Chatter Group?

Each workflow rule applies to a single object.

Universal containers would like to use a chatter group for their mergers and acquisition team to collaborate on potential new projects. This group should not be visible for non-members to see or join, and can be accessed by invite only.
Which chatter Group type should the app builder recommend?

When would a developer use upsert and external IDs? (Choose two.)