What is characterized as a service that allows simultaneous streaming of video to multiple users?

The correct answer revolves around the concept of multicast video. This service is specifically designed to efficiently deliver streaming video content to multiple users at the same time. Unlike unicast streaming, where a separate stream is established for each viewer, multicast allows a single stream to be shared among several users simultaneously, which significantly reduces the amount of bandwidth consumed. This is particularly beneficial in contexts such as broadcasting live events or distributing educational content to many viewers at once, as it optimizes resources while maintaining quality.

Other options, such as VoIP, typically focus on voice communication rather than video streaming. E-LAN is an Ethernet-based service that connects multiple sites but does not inherently involve video streaming. Point-to-point refers to a direct, permanent connection between two endpoints and is not designed for delivering content to multiple users at once. Thus, multicast video is the most appropriate choice for simultaneous streaming to multiple users.