Automatic APN selection (Windows OS)

How does the APN selection mechanism under Windows OS (e.g. 8.1, 10) work if Automatic is choosen? How does the modem select the correct APN?

My suspicion would be it looks for the MCC and MNC value which is part of the IMSI. But if there are multiple APNs used for this MCC/MNC combination, how does it go on?

Is there a check on SPN level?
And is it the modem driver which is doing this?

Kind regards