Need help with this part (B):

Buffalo Company began operations on January 1, 2015, and uses the average-cost method of pricing inventory. Management is contemplating a change in inventory methods for 2018. The following information is available for the years 2015-2017. Net Income Computed Using Average Cost Method FIFO Method LIFO Method $12,010 $16,060 $18,980 2015 20,970 2016 18,040 14,050 17,000 2017 25,130 20,180