Which of the following statements is NOT true under the perpetual inventory system?

a$.$ Since inventory shrinkage cannot be totally eliminated, it is considered a normal cost of operations.

b$.$ The balance of the inventory account is the amount of merchandise available for sale at that point in time.

c$.$ The physical inventory on hand at the end of the accounting period is usually more than the balance of Merchandise Inventory.

d$.$ The merchandise inventory account is continually updated for purchase and sales transactions.