Which approach explicitly requires an order-reference match to consume the entire JavaScr…

Which approach explicitly requires an order-reference match to consume the entire JavaScript string?

1. Test `/[A-Z]{2}-\d{6}/u` and accept any successful substring.
2. Test `/^[A-Z]{2}-\d{6}$/u` and assume `$` means only absolute end.
3. Execute `/^[A-Z]{2}-\d{6}/u`, then require `match[0].length === input.length`.
4. Add the `g` flag and call `test()` twice.