Trent uses the formula: (trade receivables at year end/revenue for the year) x 365 to calculate how long on average (in days) its customers take to pay.Which of the following would NOT affect the correctness of the above calculation of the average number of days a customer takes to pay?
选项：

A:Trent experiences considerable seasonal trading;
B:Trent makes a number of cash sales through retail outlets;
C:Reported revenue does not include a 15% sales tax whereas the receivables do include the tax;
D:Trent factors with recourse the receivable of its largest customer