What is the advantage for a Mobile Network Operator of implementing VoWi-Fi on its network?

• A. Good call quality as Home Wi-Fi offers superior data speed.
• B. Network operator saves its precious spectrum or radio resources as calls are routed through an External-IP or Public IP network.
• C. Network operator need not upgrade its Tower or Base Station hardware to support too many users. Coverage issues are solved by customers themselves by using WiFi.
• D. All