I-140 RFE should be sent to which PO box in NSC? zhanglao2007-07-24 03:52:28

P.O. Box 87140
Lincoln, NE 68501-7140

P.O. Box 82521
Lincoln, NE 68501-2521

or

USCIS
Nebraska Service Center
850 S Street
P.O. Box (Insert Correct P.O. Box Number)
Lincoln, NE 68508 ?

Just get confused.