WBJECA 2025 — Computer PYQ

Correct Option: (A) Class A

Explanation

IPv4 addresses are divided into different classes based on the range of the first octet. To determine the class, we look at the first number in the dotted-decimal notation ($\mathrm{10.5.6.7}\to 10$):

• Class A: First octet range is $1-126$.

• Class B: First octet range is $128-191$.

• Class C: First octet range is $192-223$.

• Class D: First octet range is $224-239$ (Multicast).

Since the first octet of the given IP address is 10, which falls within the range $[1,126]$, it belongs to Class A.

The classification logic can be summarized as:

$$1\le First\_Octet\le 126⟹\text{Class A}$$

$$128\le First\_Octet\le 191⟹\text{Class B}$$