Where did you apply for your immigrant visa or adjustment of status?
Where was your immigrant visa or adjustment of status issued?
-Check your I-485 Approval Notice: if the receipt number begins with three letter: EAC, then put: Vermont Service Center; if the receipt number begins with three letter: WAC, then put: California Service Center; if receipt number begins three letter: LIN, then put: Nebraska Service Center; if the receipt number begins with three letter: SRC, then put: Texas Service Center.
Same answer above for both your questions.