Which of the Following Is Desirable in a Good System

Which of the following is desirable in a good system of internal accounting control?

A) All accounting personnel in a company should be Certified Public Accountants
B) Appropriate forms, such as checks and sales invoices, should be prenumbered
C) To obtain the benefit of specialization, employees should not be rotated among jobs
D) Responsibility and authority for a given function should be shared among several employees