Final answer:
An organizational chart would be the most suitable tool to depict the changes in the chain of command after the promotion of three managers to executives.
Step-by-step explanation:
An organizational chart would be the most suitable tool to show how the chain of command has changed after the promotion of three managers to executives.
Organizational charts visually represent the structure of an organization, including the positions and reporting relationships. They use box-and-line diagrams to show who reports to whom.
In this case, the organizational chart would include three new executive positions and their relationships to the existing managers and other employees, reflecting the changes in the chain of command.