Who filed I485/I131 yourself??

My current staus is H1B with I 140 pending. My wife and son are in USA.I am filing I485 and I131 myself. I have two questions when I fill the forms. I'd appreciate it if you can help me.

1. For form I131, partI ;item3, How should I fill the "Class of Admission"? Just fill the blank with the initial visa type when I first entered USA OR the category of I485?

2. For I864 form; Should I prepare two: one for my wife, one for my son OR just one for both?

3. For I864 form, PartII: Basis for Filing Affidavit of Support: Should I choose answer:

A(I filed/am filing the alien relative petition)

OR B(I filed/am filing an alien work petition on behalf of the intending immgrant, who is related to me as my______)

Thank you in advance for your help.