The correct option is Fibre-optic cables.
Explanation
Global data transfer relies on physical transmission media capable of sustaining high bandwidth over long distances with minimal signal loss (attenuation) and latency. The comparison involves the physical properties of transmission materials and their intended scale of application.
Option Analysis:
- Fibre-optic cables is correct: Fibre-optic cables transmit data as pulses of light through strands of glass or plastic. They offer the highest bandwidth and speed capabilities among existing technologies and are immune to electromagnetic interference. Consequently, they form the backbone of the global internet, specifically through undersea cables that connect continents.
- Coaxial cables is incorrect: Coaxial cables use copper conductors to transmit electrical signals. While widely used for cable television and last-mile internet delivery, they suffer from higher signal loss over long distances and possess lower bandwidth capacity compared to fibre-optics.
- Thunderbolt Cables is incorrect: Thunderbolt is a hardware interface standard developed for connecting external peripherals (such as monitors or storage devices) to a computer. While it supports high data transfer rates, it is designed strictly for short-range connections (typically a few meters) and is not a medium for global telecommunications.
- Ethernet Cables is incorrect: Ethernet cables (typically twisted pair copper cables) are primarily used for Local Area Networks (LANs). They have significant distance limitations (usually effective up to 100 meters without signal regeneration) and are unsuitable for long-haul global transmission.
Key Takeaway: Fibre-optic technology is the standard for high-speed global telecommunications because it utilizes light signals, allowing for massive data capacity and minimal attenuation over vast distances compared to copper-based electrical transmission.