Dear,
it should be B to change the status of document
Have you tested with Completion Rule ? If yes,what was the result ?
Completion Rule A - Quotation 5 quantity ,Sales Order Order is created with 3 quantity then system will be showed the status as Completed .
Completion Rule B -Quotation 5 quantity ,Sales Order Order is created with 3 quantity then system will be showed the status as Being Processed .If you did Sales Order with 5 quantity then you will be got the Status as Complete.
First test your self and let me know the result .
Thanks,
Naren