Which of the following applications would be BEST implemented with UDP instead of TCP?

Multicast requires UDP because TCP is a unicast, connection-oriented protocol that cannot establish the one-to-many session model multicast depends on. UDP's connectionless nature also avoids the retransmission delays that TCP's reliability mechanisms would impose, which is acceptable since streaming applications can tolerate minor packet loss in favor of low latency.

A web browser uses HTTP or HTTPS, which are built on TCP to ensure reliable, ordered, error-checked delivery of web content.

DNS zone transfers use TCP because they transfer complete, large zone datasets that require guaranteed, in-order delivery to maintain data integrity.

File transfer applications rely on TCP to ensure every byte of a file arrives intact and in the correct sequence without data loss.