Question

what is a primary function of fiber - optic cables?
magnifying distant images
cutting through metals
carrying signals at high speeds
performing high - precision surgery

Explanation:

Fiber - optic cables are designed to transmit data. They use light signals. Light can travel at very high speeds (close to the speed of light in a vacuum, and in the cable, it still has a high velocity). This property allows them to carry signals (such as data for internet, phone calls etc.) at high speeds. Magnifying distant images is more related to lenses (like in telescopes). Cutting through metals is typically done with tools like metal - cutting saws (not fiber - optic cables). Performing high - precision surgery is done with specialized surgical instruments (not the primary function of fiber - optic cables which are for signal transmission).

Answer:

carrying signals at high speeds