I used AppleCare + to swap out my battered Sprint 64 GB 4S for a new refurb so that I can get more money to sell it. As I am going through the initial setup I reach a Choose Carrier screen That states "Choosing a carrier will lock this iPhone to that carrier and cannot be changed". My former phone was an unlocked Sprint phone, now on this Choose Your Carrier Screen it gives me 3 main options, Sprint, Verizon, or Virgin Mobile and a bunch of Regional Carriers. Does this setup screen mean that I can now advertize the phone as being eligible for Sprint or Verizon or Virgin Mobile customers? If so, I have a much wider potential sales base.. Please let me know. Thanks in advance