Which type of variation is best represented by a bar graph?

A bar graph is an effective way to represent discontinuous variation because it is used to display categorical data that can be separated into distinct groups. In the case of discontinuous variation, this type refers to characteristics that fall into specific categories with no intermediate values, such as blood group types or eye color. Each category can be distinctly measured or counted and represented by separate bars on the graph, which visually illustrates the differences among the categories.

In contrast, continuous variation deals with traits that show a range of measurements and can take on any value within that range, such as height or weight. Continuous data is typically represented using line graphs or histograms where the data points can be connected to show the smooth transitions between values, rather than distinct separations.

Thus, a bar graph aligns well with discrete categories relating to discontinuous variation, making it the appropriate answer in this context.