Which of the following cable types provides the highest possible transmission speed?

Plenum refers to a cable's fire safety rating for use in air-handling spaces, not its transmission speed capability.

Ethernet is a networking standard that can run over various cable types (like copper or fiber), but 'Ethernet' itself doesn't define the physical cable's maximum speed. Copper Ethernet cables (e.g., Cat6, Cat7) have lower speed limits than fiber.

Fiber-optic cables transmit data using pulses of light through optical fibers, enabling significantly higher bandwidth and transmission speeds compared to copper-based cables. They are capable of supporting multi-gigabit and even terabit speeds over very long distances with minimal signal loss.

DAC (Direct Attach Copper) cables are copper cables primarily used for short-range high-speed connections in data centers (e.g., SFP+, QSFP+), but they still have lower speed and distance limitations compared to fiber-optic cables.