A Platform Administrator has been asked to change the data type of an auto number...

In Salesforce, when a Platform Administrator changes a field ' s data type from Auto Number to Text, the operation is considered " safe " regarding data retention. The existing values that were automatically generated by the system (e.g., " INV-1001 " ) will remain unchanged and stay within the field as static text strings12. However, once the change is saved, the system will no longer increment or automatically generate new numbers for future records; users will have to enter data manually. It is important to note that the reverse operation—changing a Text field to an Auto Number—is different, as it would require the administrator to decide whether to overwrite existing data or only number new records14. Options B, C, and D are incorrect because Salesforce explicitly supports this specific conversion without deleting or fundamentally transforming the existing data into a different format other than plain text.