Which of the following statements regarding ISDN are correct?（）

• A、Each ISDN B channel has transmission speeds of up to 64 kbps.
• B、The ISDN B channel can carry video, voice or data.
• C、The ISDN B channel transmission rate varies depending on the service used.
• D、The ISDN D channel transmits control information.
• E、The ISDN B channels can be configured with different subnets and encapsulation types when dialer profiles are configured.