A custom lookup field can be added to create a relationship between a standard object and which of the following objects?

When setting up an user, the first name of the user is not required.

The system administrator has been asked to create a way to track Shipments of products to customers. Shipments should be closely tied to the Opportunity record and there may be more than one shipment record per Opportunity and the Opportunity should be required (i.e. Users cannot save a Shipment record without associating it to an Opportunity). The system administrator should create.

Which statement about custom summary formulas is true?

An active user record consumes a license.