An IP datagram larger than the network MTU (Maximum Transmission Unit) is

1. IP FRAGMENTATION (RFC 1180 §5): when a datagram is too large for the next-hop link's MTU, the router splits it into multiple fragments. 2. Each fragment has its own IP header (with the SAME source, destination, and identification) plus a fragment offset. 3. Fragments are REASSEMBLED at the FINAL DESTINATION, not at intermediate routers. 4. Modern best practice (path MTU discovery): hosts try to avoid fragmentation by discovering the smallest MTU along the path. 5. Options A, B, D are not how IP handles oversize datagrams. _Source: RFC 1180 "A TCP/IP Tutorial", §5 (Internet Protocol — Fragmentation)._