Which of the following statements is correct? Select one:

a. If the same people are responsible for a series of related accounting activities is called Segregation of Duties.

b. Auto generated document numbers is a fraud preventive method which is more efficient than physical controls.

c. Buying aged receivables from businesses and then collects the payments directly from the customers is called Allowance for uncollectible accounts.

d. Account receivable turnover is equal to net credit sales divided by average net accounts receivable