Why is UDP more suitable than TCP for applications that require low latency such as VoIP?

A. UDP reliably guarantees delivery of all packets: TCP drops packets under heavy load
B. UDP uses sequencing data for packets to arrive in order TCP offers the capability to receive packets in random order
C. TCP uses congestion control for efficient packet delivery: UDP uses flow control mechanisms for the delivery of packets
D. TCP sends an acknowledgement for every packet received: UDP operates without acknowledgments