Based on a survey of 120 adults in a city, the average number of hours each person works for pay each week is 42, with a margin of error of 1.2 hours. If the adult population of the city is 13,800, how many hours do the adults in the city work in an average week? Choose the best description of the average.
A) exactly 4830 hours
B) between 4692 hours and 4968 hours
C) exactly 579,600 hours
D) between 563,040 hours and 596,160 hours