Sound becomes hazardous noise pollution at decibels?

Answer: Option B

Sound levels are measured in decibels(dB), sound level of 80 or more dB can aptly be called noise which can cause serious hearing loss, tensions, high blood pressure, it can induce several disorders prematurely existing, such as hypertension, an increase in blood cholesterol level and is detrimental to health in other aspects when observed for more than maximum tolerable limit of 50 dB.
Hence, the correct answer is 'Above 80 dB'.