accounting information system question please solve asap

13.9 For good internal control, which of the following duties can be performed by the same individual? 1. Approve purchase orders 2. Negotiate terms with suppliers 3. Reconcile the organization's bank account 4. Approve supplier invoices for payment 5. Cancel supporting documents in the voucher package 6. Sign checks 7. Mail checks 8. Request inventory to be purchased 9. Inspect quantity and quality of inventory received The cells in the following table marked with an X indicate duties that can be performed by the same individual without creating an internal control weakness: Rationale: 1. The person who approves purchase orders should be in the purchasing function, which is also the function with the knowledge and skill to negotiate terms with supplierrs. However, the same person should not both initiate and approve purchases. 2. The cashier should sign checks, cancel the supporting documents before returning them to A/P, and mail the checks. However, the person performing these three duties should not also reconcile the bank account nor should that person approve payment of supplier invoices