Which of the Following Statements Is Not True

Which of the following statements is not true?

A) optimal inventory levels involve a trade-off between carrying costs and order costs
B) carrying costs include the cost of storing goods as well as the cost of capital tied up in inventory
C) inventory levels will be lower when storage or interest costs are high and will be higher when restocking costs are high
D) inventory level does not rise in direct proportion to sales.as sales increase, the optimal inventory level rises, but more than proportionately