According to the BABOK Guide, a data flow diagram is a tool that shows how data moves through a system or process3. A data flow diagram can help the BA determine how information is input, processed, stored, and extracted from a collection of systems, as it depicts the sources and destinations of data, the transformations and storage of data, and the flow of data between systems or processes. Therefore, the correct answer is D: References: BABOK Guide, [CCBA Mock Test]