We solve this problem by using the decibels formula which is expressed as:
dB = 10 x log (Isig/Iref)
where dB is decibels, Isig is the intensity of the signal and Iref is the intentsity of the softest sound the human ear can hear which has a value of 10^-12.
We solve as follows: dB = 10 x log (<span>1.25 x 10–4 </span>/ 10^-12 ) = 80.97 decibels
Therefore, the correct answer is option A, 81 decibels.
