question: What is the purpose of the N26 interface in the non-roaming architecture for interworking between 5GS and EPC? [3GPP Release 18] option 1: To enable interworking between EPC and the NG core option 2: To support subset of the functionalities that are supported over S10 option 3: To provide inter-CN interface between the MME and 5GS AMF option 4: To support interworking between EPC and NG-RAN 