请根据下面的CIDR写法,写出其子网掩码和网络ID()131.107.31.126/28
A:255.255.255.224131.107.31.128
B:255.255.255.240131.107.3.0
C:255.255.255.248131.107.3.64
D:255.255.255.240131.107.3.112
出自:高级计算机网络管理员