Which of the following is a common inherent risk relating to accounts payable and related expenses?

a. Management would generally prefer to record assets as expenses. 

b. Because of debt covenants requiring that the client maintain a certain level of the current ratio, management may prefer to understate accounts payable.

c. Ending inventory balances may be valued according to various accounting valuation methods. 

d. Because of the lower of cost or net realizable value requirements, it may be difficult to value accounts payable.