Which chart effectively represents the flow and amount of data traffic?

The Sankey Diagram is the correct choice for effectively representing the flow and amount of data traffic. This type of diagram is specifically designed to visualize the movement of quantities between different states or categories, making it particularly useful for illustrating the flow of data through a system.

In a Sankey Diagram, the width of the arrows is proportional to the flow of data, which allows viewers to quickly grasp not only the connections between different stages or areas but also the volume of data being transferred. This visual representation aids in identifying major pathways and bottlenecks in data traffic, facilitating better analysis and decision-making.

In contrast, while bar charts can show quantities across different categories, they do not effectively convey the flow of data between those categories. Line graphs are excellent for showing trends over time but lack the ability to illustrate multiple flows at once. Pie charts represent parts of a whole and do not provide insight into directional flows or comparative quantities across different pathways. Thus, the visual design and emphasis on flow make the Sankey Diagram the most suitable choice for representing data traffic effectively.