I think the correct option in this case is a. It reads "(Atttach a copy of the approval notice-- or a relative, special immigrant juvenile or special immigrant military visa petition filed with this application that will give you an mmediately
available visa number, if approved.)"
Since you are filing concurrently with the I130, the I130 is the relative petition mentioned in the section above. I intend to use this option when I file my application, but it is always advisable to double-check with an attorney.