IP options in fragments are replicated only if the high-order bit is set to 1.

• A. Replicated only if high-order bit is 1
• B. Replicated in all fragments
• C. Not replicated in any fragment
• D. Replicated only in the last fragment

Answer: (A)

In IPv4, the options field in the IP header includes a per-option copy flag. This high-order bit tells routers whether that option should be carried in every fragment when a packet is fragmented. If the bit is 1, the option is replicated across all fragments; if it is 0, the option appears only in the first fragment. So saying that IP options in fragments are replicated only if the high-order bit is set to 1 exactly describes how fragmentation handles options. For example, options like Record Route typically have this bit set and thus show up in all fragments, while options with the bit clear would not be replicated.