The correct answer is: B. Deci
A decibel (dB) is a logarithmic unit that expresses the ratio of a physical quantity (such as sound pressure) to a reference value. The reference value is often 0 dB, which is the threshold of human hearing.
A phon is a unit of perceived loudness, not sound pressure. It is based on the subjective response of human hearing, and is not directly proportional to sound pressure level.
A decibel is a unit of sound pressure level, which is a measure of the intensity of a sound. The decibel scale is logarithmic, which means that a change of 10 dB represents a tenfold increase in sound pressure.
A decimal is a
number that is written using the decimal system, which is a system of counting that uses ten as the base. The decimal system is the most common system of counting in use today.I hope this helps! Let me know if you have any other questions.