Detailed Answer
Answer (D) is correct. One person should not be responsible for all phases of a transaction, i.e., for authorization, recording, and custodianship of the related assets. These duties should be performed by separate individuals to reduce the opportunities for any person to be in a position of both perpetrating and concealing errors or fraud in the normal course of his or her duties. For instance, an employee who receives and lists cash receipts should not be responsible for comparing the recorded accountability for cash with existing amounts.