It is suspected that key e-mails have been viewed by unauthorized parties. The e-mail administrator conducted an investigation but it has not returned any information relating to the incident, and leaks are continuing. Which of the following is the BEST recommended course of action to senior management?

A. Commence security training for staff at the organization.
B. Arrange for an independent review.
C. Rebuild the e-mail application.
D. Restrict the distribution of confidential e-mails.