Class B, if you are referring to classful addressing schemes.
The difference between classful IP addressing and classless IP addressing is in selecting the number of bits used for the network ID portion of an IP address. In classful IP addressing, the network ID portion can take only the predefined number of bits 8, 16, or 24. In classless addressing, any number of bits can be assigned to the network ID.
The IP address is of class C.
security
Class C
In classful addressing, the class of an IP address can be determined by the value in the first octet: 0 - 126 class A 128 - 191 class B 192 - 223 class C
The first octet determines the class, so-0-127 is Class 1128-191 is Class 2192-223 is Class 3So the IP address 203.12.176.55 is a Class 3 address.
If the first byte is in the range 192-223, that's a class C address.
For multicast, ip addresses in the range of 224.0.0.0 - 239.255.255.255 are used.
Static IP
Class D
rip version 1 is classfull routing protocol. in classfull routing protocol is not able to carry its subnet mask whatever the ip belong from a class. it wil take its by default subnet mask.if the ip address belong to class b and the subnet mask is published as /28. in classless routing protocol this ip address would be displayed as /16 not like /28