How Can Companies Prevent Salespeople and Sales Managers from Manipulating

How can companies prevent salespeople and sales managers from manipulating the system to artificially inflate sales?

A) Companies can add in safeguards that no sales can be entered into the ordering system without sign-off from two managers.
B) Companies can prevent anyone but a central ordering clerk from entering any sales into the system.
C) There is no way to prevent manipulating the system completely,as unethical sales representatives and managers will be able to find loopholes if they are motivated to.
D) Salespeople should be asked to sign an affidavit with each order submitted that the order is real and not falsified.
E) Salespeople who falsify sales should be liable for legal penalties to both the company and the defrauded customers.