(B) will be answer
A data flow diagram (DFD) is a graphical representation of the "flow" of data through an information system, modelling its process aspects. ADFD is often used as a preliminary step to create an overview of the system without going into great detail, which can later be elaborated.
There are two types of DFD:
The logical DFD describes the business events that take place and the data required for each event. It provides a solid basis for the physical DFD, which depicts how the data system will work, such as the hardware, software, paper files and people involved.