Which option describes what happens when a labelled packet with a TTL of 1 is received by an LSR?
A. The packet is forwarded on to the next router where its TTL expires and from where an ICMP “time exceeded” message is generated and routed back to the source.
B. The packet is dropped and an ICMP “time exceeded” message is IP routed back to the sender.
C. The packet is dropped and an ICMP “time exceeded” message is label-switched from the expiring router back on a new path toward the source.
D. The packet is dropped and an ICMP “time exceeded” message is label-switched from the expiring router on the same label switched path toward the destination and then back to the originating source.
E. The packet is forwarded on to the next router where its TTL expires and from where an ICMP “time exceeded” message is generated and label switched back to the source.
