Each year, company X signs a contract with shipping firm Y, stating that shipping firm Y will do all the company's international shipping. Shipping firm Y has a policy called "natural increases," which raises the price for the service that it provides to company X each year by an inflation-commensurate percentage of the previous year's shipping rates. This new price then becomes the baseline for the next year's increases; this policy is intended to let shipping firm Y make profits that keep pace with inflation.

Which of the following statements, if true, is the best basis for a criticism of "natural increases" as an economically sound practice for company X as it exists as part of the international shipping contract?

• ACompany X's stockholders believe that Company X regularly spends more than it should on shipping costs.  
• BThis practice may cause company X to spend an increasingly large proportion of their profits on shipping as company Y's costs rise.  
• CThe rate of inflation has varied significantly over the past decade.  
• DIf shipping firm Y overcharged company X in the past, then company X will continue to overpay for shipping services.  
• EThe pricing method based on "natural increases" may discourage initiatives for company Y to develop and utilize new shipping routes.