Comprehensive and Detailed Step-by-Step Reference Field Type: The Reference field type is used to create a relationship between two tables. It allows you to select and display records from another table directly on a form. For example, adding a "Caller" field to an Incident form enables you to query and select records from the sys_user table. Why Other Options Are Incorrect: Option B (Phone Number field type): This is used for storing phone numbers, not for querying records from another table. Option C (String field type): While this stores plain text, it does not allow querying or establishing relationships with other tables. Option D (Date field type): This is used for date or time values, not for referencing another table. Reference: ServiceNow Developer Documentation on Field Types.