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