Algebra 2 ?

5. a construction explosion has an intensity i of 1.25 x 10–4 w/m2. find the loudness of the sound in decibels if w/m2. round to the nearest tenth. (1 point)

81 decibels
161 decibels
82.2 decibels
12.5 decibels

the example question in the textbook is totally different so i'm not sure how to do this. i tried to make the equation and then got confused. an explanation would be great!