Final answer:
The context diagram is the least detailed data flow diagram as it provides an overview without the internal process details found in other diagrams.
Step-by-step explanation:
The context diagram is known to be the least detailed among the options provided for data flow diagrams. This type of diagram serves as the top level or starting point and provides an overview of the system interface to the external entities. It summarizes all data inputs and outputs but does not detail the internal workings or the process flow within the system, making it less detailed than the logical data flow diagram, the systems flowchart, or the physical data flow diagram, which provide more layers and complexity of the system's processes.