G-325A Biographic Info Question

My husband and I filled these forms out to the best of our ability (confusing!  Won't even let me put my mother's last name on there). 

There is one part, however that we can't seem to figure out.  There is a part of the form where it says...

"This form is submitted in connection with an application for:"

Which one should my husband and I each put?  The options are:

1. Naturalization
2. Status as permanent resident
3. Other (specify) _____


Any help is appreciated.  Thanks!

Check "other" and write  I-130 petition

We just sent ours this week and they have already charged our credit card.