Which of the following regarding protocol states is true?

The correct answer is B .

The study guide states that for TCP , the protocol state is a two-digit number . The first digit is the server-side state and is 0 when the session is not subject to inspection . The second digit is the client-side state . It also shows that value 1 = ESTABLISHED

So, for a normal TCP session with no inspection, proto_state=01 means:

first digit 0 = no inspection

second digit 1 = ESTABLISHED

That makes B correct.

Why the other options are wrong:

A is wrong because for UDP , the study guide says 00 = one-way traffic and 01 = two-way traffic

C is wrong because 10 does not represent the normal established TCP session described in the study guide. The established example shown is based on state value 1 , and the guide explicitly highlights proto_state=11 when both server-side and client-side TCP handshakes are completed

D is wrong because for ICMP , the study guide says “the protocol state is always 00”

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