. GROUP BY by itself creates subtotals by category, and the ROLLUP extension to GROUP BY creates even more categories for subtotals. Using all the orders, do a rollup to get total order amounts by product, sales region, and month and all combinations, including a grand total. Display the results sorted by product, region, and month. Put your query and the first portion of the answer set, including all of product 1 and a few rows for product 2, into a file for your instructor. Also, do a regular GROUP BY and put this query and the similar results from it into the file and then place an explanation in the file of how GROUP BY and GROUP BY with ROLLUP are different.