Question: Who can provide Roaming Value-Added Services (RVAS) in a 5G system?
Option 1: Only the Home Public Land Mobile Network (HPLMN)
Option 2: Any untrusted third-party entity
Option 3: A fully trusted entity, which could be any trusted 3rd party acting on behalf of the PLMN
Option 4: The serving Public Land Mobile Network (VPLMN) only
Explanation: In a 5G system, RVAS can be provided by a fully trusted entity, which could be any trusted 3rd party acting on behalf of the Public Land Mobile Network (PLMN). This allows for flexibility in the provision of value-added services while ensuring that security and trust are maintained.