Which of the following technique is used for Time-To-Live (TTL)?

• A. one of the pieces that results when an IP gateway divides an IP datagram into smaller pieces for transmission across a network that cannot handle the original datagram size.
• B. a technique used by protocols in which a lower level protocol accepts a message from a higher level protocol and places it in the data portion of the low level frame.
• C. a technique used in best-effort delivery system to avoid endlessly looping packets.
• D. all of the above