Martinez Company began operations on January 1, 2018, and uses the average-cost method of pricing inventory. Management is contemplating a change in inventory methods for 2021. The following information is available for the years 2018-2020. (a) Prepare the journal entry necessary to record a change from the average cost method to the FIFO method in 2021. (Credit account titles are automatically indented when amount is entered. Do not indent manually. If no entry is required, select "No Entry" for the occount titles and enter o for the amounts.) (b) Determine net income to be reported for 2018,2019 , and 2020, after giving effect to the change in accounting principle. (c) Assume Martinez Compary used the UFO method instead of the average cost method during the years 2018-2020. In 2021. Martinez changed to the FIFO method. Prepare the journal entry necessary to record the change in principie (Credit account tities ore automatically indented when amount is entered Do not indent manually. If no entry is required, select "No Entry" for the account titles and enter 0 for the amounts.)