When it comes to fraud committed by an organization’s employees, the single most effective fraud prevention technique is

 

    "Creating the perception that fraud will be detected and punished" .


Source:

         An online search reveals a particular web page from "Coursehero" — which shows this very question being asked:

      "When it comes to fraud committed by an organization’s employees, the single most effective fraud prevention technique is ."

→ and continues with the following answer choices:

"a. Holding managers responsible for the actions of their employees 
 b. Peer monitoring (employees monitor each other) 
 c. Creating the perception that fraud will be detected and punished 
 d. A clearly written employee policy manual that explains unacceptable                behaviors 
 e. All of the above " ;

 Source:  "coursehero" {Date viewed/accessed:  25 Apr 2018.}. 

The correct answer—from the choices provided— is:  

   "Creating the perception that fraud will be detected and punished" .