Question 4 In a Class A address, the possible values for the first octet are: 1 point255 through 4200 through 1270 through 255128 through 199

Break Down the Problem

1. Identify the range of values for the first octet of a Class A IP address.
2. Determine which of the given options correctly includes the range for Class A addresses.

Relevant Concepts

• Class A addresses are defined in the IP address standard.
• The first octet of a Class A address ranges from 1 to 126.

Analysis and Detail

1. The range for a Class A IP address:
   • Starts from 1 and goes up to 126.
   • The values 127.x.x.x are reserved for loopback addresses and are not included in Class A public addresses.

Verify and Summarize

Now let's analyze the provided options:

• 255 through 420: Invalid range.
• 200 through 127: Partially valid; only numbers 1 to 126 are valid.
• 0 through 255: Valid in terms of range but not focused on Class A.
• 128 through 199: Invalid range for Class A.

None of the given ranges perfectly reflect the Class A requirement; however, the closest partial range is 200 through 127, but since it doesn't directly confirm to the check (1 to 126), it can mislead.

Final Answer

The correct range for the first octet of a Class A IP address is from 1 to 126. None of the provided options perfectly reflects this range.