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