Which of the Following Is TRUE Regarding the Segregation of Duties

Which of the following is TRUE regarding the segregation of duties in the purchasing process?

A) The authority to approve disbursement vouchers should be separate from the authority to sign checks.
B) Segregation of computerized functions can be attained through the use of passwords, file/record locks, and designated terminal access.
C) The password system allows a receiving clerk to read, but not write to, an open purchase order.
D) All of the above are true regarding the segregation of duties in the purchasing process.