Question: What protocol is used to transfer subscription and authentication data between MME and HSS for authenticating/authorizing user access to the evolved system?
Option 1: Diameter
Option 2: Stream Control Transmission Protocol (SCTP)
Option 3: General Packet Radio Service (GPRS)
Option 4: Evolved Universal Terrestrial Radio Access Network (E-UTRAN)
Explanation: Diameter is used to transfer subscription and authentication data between MME and HSS for authenticating/authorizing user access to the evolved system, as it supports transferring of such data.