What type of map is used for comparing and contrasting two subjects?

The correct choice is the double bubble map, which is specifically designed for comparing and contrasting two subjects. This visual tool allows users to create a systematic and clear representation of the similarities and differences between the two subjects being analyzed. Each subject is typically represented by a bubble, and overlapping areas illustrate shared traits or characteristics, while the areas unique to each bubble highlight distinctions. This format supports critical thinking by encouraging analysis of how the subjects relate and diverge, which is essential in both academic discussions and problem-solving scenarios.

In contrast, a tree map is used to represent hierarchical data, a bubble map focuses on describing qualities of a single subject, and a multi-flow map is useful for demonstrating cause-and-effect relationships rather than direct comparisons. This distinction in functionality makes the double bubble map the most suitable choice for comparing two subjects effectively.