Optical fibers can transmit analog or digital signals.

• A. Some of them
• B. Only digital
• C. True
• D. False

Answer: (C)

Optical fibers carry information by modulating light, and that modulation can be analog or digital. The fiber itself is a guided-light channel with low loss, so it doesn’t impose a digital-only constraint. Analog signaling uses continuous changes in light intensity, phase, or frequency to represent a waveform, like varying audio or video signals. Digital signaling uses discrete on/off or other modulation schemes to encode bits. Because the medium simply transmits light, it can carry either type as long as the transmitter and receiver are designed for the chosen modulation and bandwidth. The other options don’t fit because they either limit the medium to one type or suggest the fiber can’t carry analog signals at all.