dN is a standard abbreviation used for the quantitative expression of

Options

A. the density of bacteria in a medium
B. a particular pollutant
C. the dominant Bacillus in a culture
D. a certain pesticide

Answer

B

Explanation

Noise pollution is a physical form of pollution that affects the receiver directly affecting the nervous system which result into various disorders in humans. dB (decibel) is a standard abbreviation used for the quantitative expression of noise. Noise or pollutant sound has a value of 80 dB and above, it harms hearing system. The WHO has fixed 45 dB as the safe noise level for a city.