What type of field can be used to filter a report chart that has been added to page Layout?

Universal Containers is setting up salesforce for the first time. Management wants the sales and marketing teams to have different navigation names in the salesforce1 mobile app. Which option is available to an app builder to satisfy the requirement?

UVC has two types of customer support processes: Platinum and Diamond. The App Builder created separate record types for each process on the Case Object. The customer support team should not be able to create new cases with the Diamond record type. How can this requirement be met?

In order to delete a record smth needs to be approved.

At Universal Containers, the Account object has a Master-Detail relationship with an Invoice custom object. The App Builder would like to change to a lookup field, but is not able to do so. What could be causing this?