Under the periodic inventory system, what is the correct entry to record the cost of the sale of a dining suite sold to a customer for $1650 including 10% GST? (The dining suite was originally purchased on credit for $990 including GST of $90). a. DR Cost of sales $900; CR Inventory $900 b. DR Purchases $900; CR Inventory $900 c. The cost of each sale is not recorded under the periodic inventory system d. DR Purchases $1650; CR Sales $1650