Which of the Following Is Not Characteristic of Perpetual Inventory

Which of the following is not characteristic of perpetual inventory systems?

A) The inventory account is continually adjusted for each change in inventory caused by a purchase or sale.
B) Accurate inventory systems allowing management to determine how many items are on hand at any given date.
C) Periodic inventory counts are taking at least annually.
D) All of the above are characteristic of perpetual inventory systems.