Which statement best explains how tone transmission conveys the measured value?

Which statement best explains how tone transmission conveys the measured value?

• A. A digital packet containing time-stamped data.
• B. A radio frequency carrier with amplitude encoding the value.
• C. A continuous stream of binary bits conveying the measurement.
• D. A pure audible tone whose duration represents a measured value.

Answer: (D)

Tone-based transmission encodes information in the time dimension: how long a tone plays carries the value. In this approach, the sender produces a pure audible tone and lets it continue for a specific duration that maps to the measured value. The receiver then measures that duration and converts it back to the numeric value. This direct link between tone length and value makes duration the mechanism by which the measurement is conveyed. Other options describe data being carried by packets, carriers with amplitude encoding, or continuous binary streams—methods that rely on different signal properties (structure, frequency, or bit sequences) rather than simply how long a tone lasts.

Tone-based transmission encodes information in the time dimension: how long a tone plays carries the value. In this approach, the sender produces a pure audible tone and lets it continue for a specific duration that maps to the measured value. The receiver then measures that duration and converts it back to the numeric value. This direct link between tone length and value makes duration the mechanism by which the measurement is conveyed. Other options describe data being carried by packets, carriers with amplitude encoding, or continuous binary streams—methods that rely on different signal properties (structure, frequency, or bit sequences) rather than simply how long a tone lasts.