A user is unable to reach the Internet. The technician asks the user to do an IPCONFIG \/all. The userreports that their IP address is 172.16.18, subnet mask is 255.255.255.0, and their default gateway is 172.16.18. Which of the following is the cause of the problem?（）
A. Default gateway
B. Network cable
C. Subnet mask
D. CNAME record
参考答案：A
