Which statement correctly describes tone transmission?

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

Answer: (B)

The key idea is that tone transmission encodes the value by how long a tone sounds. A pure audible tone is generated at a fixed frequency, and the measured value is determined by the duration the tone is on. This matches the concept of using time to convey information rather than changing the frequency shape, packaging data into digital frames, or modulating a carrier.

Why the other descriptions don’t fit as tone transmission: a continuous stream of binary bits describes a raw digital data stream rather than a single tone whose length encodes value; a digital packet with time-stamped data implies structured data with headers and formatting rather than a single tone’s duration; a radio frequency carrier with amplitude encoding describes amplitude modulation of a carrier, not a simple tone whose duration carries the measurement.