Which statement accurately describes a master key system?

Which statement accurately describes a master key system?

• A. A master key system uses a single level of key operation with one key for all locks
• B. A master key system uses no master keys and each lock has its own unique key
• C. A master key system uses two or more levels of key operation with a master key that can fit all locks
• D. A master key system eliminates the need for key control

Answer: (C)

The important idea here is hierarchical keying: access is organized in levels, with a master key that can open a wider set of locks than a regular change key. In a master key system, each lock has its own change key that opens only that lock. There are one or more master keys that can open a defined group of locks, and often a top-level master key that can open all locks in the system. This structure lets you grant different levels of access—an individual user can open their own lock, a supervisor can open all locks in their area, and an administrator can open every lock in the building. So this statement is best because it describes multiple levels of key operation and the presence of a master key that can fit all locks, which is the essence of a master key system. The other options describe either a single-key arrangement, a system with no master keys, or claim that key control is eliminated, which doesn’t fit how master key systems are designed to function.

The important idea here is hierarchical keying: access is organized in levels, with a master key that can open a wider set of locks than a regular change key.

In a master key system, each lock has its own change key that opens only that lock. There are one or more master keys that can open a defined group of locks, and often a top-level master key that can open all locks in the system. This structure lets you grant different levels of access—an individual user can open their own lock, a supervisor can open all locks in their area, and an administrator can open every lock in the building.

So this statement is best because it describes multiple levels of key operation and the presence of a master key that can fit all locks, which is the essence of a master key system. The other options describe either a single-key arrangement, a system with no master keys, or claim that key control is eliminated, which doesn’t fit how master key systems are designed to function.