Which of the following is an interface standard designed for high-speed serial bus communications?

Firewire, also known as IEEE 1394, is an interface standard specifically designed for high-speed serial bus communications. It is particularly known for its ability to connect devices and transfer data at high speeds, such as for video and audio applications. Firewire supports data transfer rates that can reach up to 800 Mbps in its later iterations, making it suitable for situations where large amounts of data are transferred quickly, such as during video editing or streaming.

The other options, while they serve various communication standards, do not specifically highlight high-speed serial communication in the same context. USB (Universal Serial Bus), for example, is versatile and widely used but generally focuses on connecting peripherals and has different versions with varying speeds. Ethernet, on the other hand, is primarily used for networking and is not classified as a serial bus standard. Bluetooth is a wireless technology used for short-range communication, which also does not directly fall under high-speed serial bus communication. Thus, Firewire stands out as the correct choice for this particular context.