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？（）

1. A Block both IRC and ICMP
2. B Utilize SNMP to identify IM users
3. C Contact the IM carrier to request the IM account be disabled
4. D Change the shaping setting to allow minimal traffic to reduce port hopping 正确答案