A developer Is Integrating with a legacy on-premise SQL database. What should the developer use to ensure the data being Integrated is matched to the right records in Salesforce?

A Lookup field creates a relationship between two Salesforce objects using their internal Salesforce IDs and is not designed for matching records based on external system identifiers.

An External ID field in Salesforce stores a unique identifier from an external system, allowing developers to use this ID for matching records when performing upsert operations or integrating data, ensuring accurate data synchronization.

A Formula field calculates its value based on other fields and is read-only, making it unsuitable for storing and actively using external system identifiers for record matching.

An External Object (part of Salesforce Connect) allows real-time access to external data but does not primarily serve as the mechanism for matching records from an on-premise database during integration processes like data import or upsert.