In recent years, networks of fiber-optic cable have been replacing electrical wire for transmitting telecommunications signals. Signals running through fiber-optic cables deteriorate, and so the signals must be run through a piece of equipment called a regenerator before being transmitted farther. Light-Line is the leading manufacturer of signal regenerators. Therefore, Light-Line is one of the companies that will most benefit if new long-distance fiber-optic telecommunications networks are constructed.
Which of the following, if true, casts the most doubt on the prediction about Light-Line's prospects?

【选项】The volume of signals that a fiber-optic cable can carry is several thousand times greater than the volume that can be carried by an electrical wire of similar size.