Answer: Unity of command principle
Explanation:
The chain of command is basically defined as the command which is unbroken line of the authority and extends the level of the organization from top to lowest level echelon. It basically clarifies the individual report.
The unit of command is the principle that helps to preserve the main concept of the line of authority in an organization.
Most of the organization finds very effective way of command. The unit of command basically help to preserve this chain of command authority and also preserve it from the various structural characteristic of matrix as it break the unit of command.