Final answer:
The branch manager's disciplinary action demonstrates the dimension of control and accountability in ethical behavior in the digital age.
Step-by-step explanation:
The disciplinary action taken by the branch manager demonstrates the dimension of ethical behavior in the digital age known as control and accountability. By reprimanding the employee and withholding a promotion, the manager is holding the employee responsible for their inappropriate use of a customer's personal email address. This action reinforces the importance of following ethical standards and maintains accountability within the organization.