A company wants all IM chat via the internet to stop. A technician blocks IRC traffic with a traffic shaping device， yet IM chat remains useable. Which of the following should a technician do next？（）

• A、Block both IRC and ICMP
• B、Utilize SNMP to identify IM users
• C、Contact the IM carrier to request the IM account be disabled
• D、Change the shaping setting to allow minimal traffic to reduce port hopping