Host A(on TCP/IP v4 network A) sends an IP datagram D to host B (also on TCP/IP v4 network B) Assume that no error occurred during the transmission of D. When D reaches B, which of the following IP header field(s) may be different from that of the original datagram D?
i) TTL ii) Checksum iii) Fragment Offset
1. (i) only
2. (i) and (ii) only
3. (ii) and (iii) only
4. (i), (ii) and (iii)