Which of the following actions describes a best practice that management should take to preserve...

A key confidentiality practice is to warn those involved in the investigation not to transmit confidential case information through unsecured email or similar insecure channels. Fraud investigations should be handled on a need-to-know basis, and sensitive information should be protected from unnecessary disclosure. Option A is too broad because suspending all involved employees might be unnecessary, disruptive, and unfair. Option B is not required; private investigations do not automatically need government supervision. Option C is also too broad because blanket gag rules can create legal and labor-law problems in some jurisdictions. The better approach is controlled communication, secure handling of information, and limiting access to those who need the information to perform their duties. Therefore, option D is correct.