Correct Answer: B. Fiber

Fiber-optic technology transmits information using pulses of light through optical fibers rather than electrical signals through metallic conductors.

Because optical fibers use light as the transmission medium, they are inherently immune to electromagnetic interference (EMI) and radio-frequency interference (RFI) that can disrupt electrical communication systems.

Fiber-optic cables are particularly suitable for environments containing electrical machinery, high-voltage equipment, industrial motors, and other sources of electromagnetic interference.

Additional advantages include high bandwidth capacity, long-distance transmission, and electrical isolation between connected devices.

Why the other options are incorrect:

A. Copper: Copper cables transmit electrical signals and can experience electromagnetic interference from nearby electrical equipment.

B. Fiber: Optical fiber carries light signals and is not susceptible to conventional electromagnetic or radio-frequency interference.

C. Wireless: Wireless networks depend on radio-frequency communication and can experience interference from other wireless devices, overlapping channels, and environmental factors.

D. Twisted pair: Twisted-pair cabling uses copper conductors. Twisting helps reduce electromagnetic interference and crosstalk but does not eliminate susceptibility completely.

Therefore, Option B is correct because fiber-optic cabling provides immunity to conventional EMI and RFI affecting copper-based and wireless network technologies.