Which of the following would be the best protection for a company that wishes to prevent the “lapping” of trade accounts receivable?

Which of the following would be the best protection for a company that wishes to prevent the “lapping” of trade accounts receivable?

    a.    Segregate duties so that the bookkeeper in charge of the general ledger has no access to incoming mail.
    b.    Segregate duties so that no employee has access to both checks from customers and currency from daily cash receipts.
    c.    Have customers send payments directly to the company’s depository bank.
    d.    Request that customer’s payment checks be made payable to the company and addressed to the treasurer.