What type of services are provided by the Cisco IOS gateways in a VoIP network with Cisco CallManger functionality？（）
- ACisco IOS gateways provide services such as address translation and network access control for the devices on the network
- BCisco IOS gateways provide services such as bandwidth management and accounting
- CCisco IOS gateways provide media termination and signal translation between the public switched telephone network （PSTN） and IP networks
- DCisco IOS gateways provide zone management for all registered endpoints in the network