What are two uses for External IDs? (Choose two.)
What are two uses for External IDs? (Choose two.)
External IDs in Salesforce can be used for two main purposes: First, they help create relationships between records imported from an external system. This allows data integration and linking data from other systems to Salesforce. Second, they are used to prevent an import from creating duplicate records using the Upsert operation. The Upsert operation utilizes the External ID to determine if a record already exists; if it does, the record is updated; if it does not, a new record is created, thus preventing duplicates.
While A is the most correct answer the wording is very ambiguous, it's a relationship between data from the external system and the salesforce record, not between salesforce records. You can indeed create a "soft" link but there will not be an official relationship (lookup or master detail) in salesforce.