Which of the following is correct regarding Dataflowdiagram?

? Single DFD is required to represent a system

? the dataflow must be bidirectional

? Created at increasing levels of detail

? Used to represent the relationships amongthe external entities

Answer: Used to represent the relationships among the external entities

Explanation:

Data flow diagram is used to represent the relationship among the external entities as, it is used to represent the data based on input and output of the system. External entities basically used to produced the data flow between the system and the external entities. It is being analysed by the external system as, these entity are placed at boundary of the diagram.