An important limitation of the Cisco Business Ready Teleworker solution is_____.（）

• A、IP phone extensions for teleworkers must be chosen carefully so not to duplicate campus phone extensions.
• B、More security exposure exists due to lack of support for Intrusion Detection System and URL filtering for teleworker originated traffic.
• C、Compressed RTP and IPSec are not compatible and result in no bandwidth savings.
• D、Broadband modems must support Quality of Service for adequate voice quality.