Which of the following is not a typical problem found by auditors when cleansing client data for the purposes of performing an ADA? 

a. Some fields may be empty and thus cause errors during analysis. 

b. Some fields may not be sorted in numerical order and require sorting for identification of outliers. 

c. Some date fields may contain letters or be in the wrong format. 

d. Some fields may have country-specific differences such as currency.