Inventory valuation

If an entity uses the continuous weighted average cost method to value closing inventory, Which of the following statements is true? A Unit average cost is recalculated each time there is a purchase of inventory B Unit average cost is calculated once only at the end of an accounting period C Unit average cost is recalculated each time there is a sale of goods D Unit average cost is recalculated each time there is a purchase or a sale kit says the answer is A. But I think the answer is C. We calculate cost per unit in continuous weighted average, each time there is a sale of goods please correct me sir, if I'm wrong