What is the binary bit pattern of the first octet of a class B IPv4 address?

The binary bit pattern of the first octet of a class B IPv4 address is defined by its structure. In IPv4 addressing, the first octet indicates the class of the address. For class B addresses, the first two bits are fixed as '10', which designates it as a class B address. The remaining six bits, represented as 'xxxxxx', can vary, allowing for a range of addresses within class B.

This structure allows for class B addresses to range from 128.0.0.0 to 191.255.255.255. The addressing scheme is crucial for understanding how to categorize and assign IP addresses within networks. Therefore, the correct representation in binary—starting with '10'—is accurately conveyed with the bit pattern provided.