Universal Containers needs the 18-digit record ID from Opportunity records when exporting data to Excel...

The app builder should use the CASESAFEID(Id) formula to create this new field. The CASESAFEID function returns the 18-digit case-insensitive version of the record ID, which is unique for each record in Salesforce. The 18-digit record ID is useful for exporting data to external systems that require case-sensitive IDs1. Option A, C, and D are not formulas that can return the 18-digit record ID.