Which of the following is most likely to be an example of fraud?

a. The auditor fails to properly determine the reason why so many of the client's customers complain that they have been overcharged.

b. The auditor allows an important footnote describing a large contingent liability to be omitted from the financial statements.

c. The auditor miscounts the amount in the client's cash funds.

d. The auditor forgets to observe inventory-taking at a client's place of business when inventory is a significant amount in the client's balance sheet.