a. Use the purchase_items table to calculate the dollar amount of each item purchased in an extension query; name your new calculated field purchase_item_amount and format it appropriately. b. Use qa and the purchases table to sum the purchase item amounts for each purchase in an accumulation query; include all fields from the purchases table and the purchase_item_amount field from qa; name your summed field purchase amount and format it appropriately. C. Use qb and the vendors table to sum the purchase amounts from each vendor in another accumulation query; include vendor number, name, city, and state; name your summed field vendor purchases and format it appropriately. d. Use the qb query. Keeping all fields from qb, calculate the month of the purchase; name that field purchase month