Answer:
C. written rules.
Explanation:
Discretion inside an organization is mostly controlled by written rules, for example: non-disclosure agreements, or confidentiality agreements that last for months or even years after the signing employee leaves the firm.
This is because no matter how good an employee is, or how much he was trained, or how many meetings he attends, he still needs to know exactly what he is allowed and not allowed to say, and written rules are the easiest way to clarify this.
