The app builder should create a new roll-up summary field called First Order Date, using Type MIN on the Opportunity Close Date with a filter where IsWon = TRUE. A roll-up summary field is a type of field that calculates values from related records and displays them on the parent record. In this case, the app builder can create a roll-up summary field on the Account object that calculates the minimum (earliest) value of the Opportunity Close Date field from the related opportunities where IsWon = TRUE. This will show when customers made their first purchase. Option B, C, and D are not correct ways to use a roll-up summary field to meet the requirement.