单项选择题
A.17 B.6 C.23 D.1
A.10.110.16.1和10.110.33.2 B.172.16.44.33和172.16.56.34 C.192.168.135.56和192.168.143.23 D.202.117.15.45和202.117.17.48
A.10.0.0.0/8 B.172.16.0.0/12 C.192.168.0.0/16 D.224.0.0.0/8