What is an example of a polymorphic lookup field in Salesforce?
A. The Parentid field on the standard Account object
B. The LeadId and ContactId fields on the standard Campaign Member object
C. A custom field, Link c, on the standard Contact object that looks up to an Account or a Campaign
D. The Whatld field on the standard Event object
D. The Whatld field on the standard Event object
Explanation:
A polymorphic lookup field in Salesforce can reference multiple object types. The most common examples are:
WhatId on Event (D):
Can reference multiple standard objects (e.g., Account, Opportunity, Case, Custom Objects).
Used to associate an Event with any of these records.
Other Polymorphic Lookups:
ParentId (Task): References Leads, Contacts, and other objects.
WhoId (Event/Task): References Contacts or Leads.
Why Other Options Are Incorrect:
A: ParentId on Account is not polymorphic (only references Account for hierarchy).
B: LeadId and ContactId are separate fields, not a single polymorphic field.
C: Custom fields cannot be polymorphic (only standard fields support this).