An auditor suspects that ficticious sales may have been recorded during the year. Which of the following analytical review results would most likely indicate that fictitious sales were recorded? Answer a. Gross margin decreased from 40 to 35%. b. Uncollectible account write-offs increased by 10%, sales increased by 10%, and accounts receivable increased by 10%. c. Accounts receivable turnover decreased from 7 to 4. d. The number of day's sales in accounts receivable decreased from 64 to 38