What is a true statement in regard to creating custom report types?

Universal Containers wants to improve the process to create Opportunity records related to an Account. Many fields can be populated based on the Account record. Some fields require input from the user.
What should an app builder configure to meet the requirement?

Universal containers needs to flag leads with one or more business areas. They need to add a field to capture these to the lead records. There is no need to report on this field. What is the appropriate field type?

Which of the following can be source of report chart placed in page layout?(Choose 2)

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?