Final answer:
Multicast communication is a method of transmitting data from one source to a specific group of receivers on a network, making it the correct term for one-to-many host communication.
Step-by-step explanation:
One-to-many communication between one source and a specific group of hosts is classified as multicast communication. Multicast is a network method used to send network packets to a group of listeners at different locations, forming a multicast distribution tree. Unlike unicast that targets a single receiver with a single packet, multicast sends a single stream of data to multiple receivers. It is efficient for streaming media, online gaming, and various other network services. Broadcast communication sends packets to all hosts on the network, regardless of whether they are interested in receiving the data or not. Duplex communication relates to the ability to send and receive data (such as in full-duplex or half-duplex modes), and is not specifically related to a message's distribution concept.