Final answer:
Communication and diffusion relate to the themes of Movement and Human-Environment Interaction in geography, which encompass the spread of ideas and cultural phenomena and the reciprocal relationship between humans and the environment.
Step-by-step explanation:
Communication and diffusion refer to the processes by which items or ideas spread and integrate into various cultures. Diffusion, in the context of geographic themes proposed by the Association of American Geographers, is closely related to the theme of Movement. This is because diffusion involves the movement or spread of cultural phenomena, like the Columbian Exchange, or the spread of popular culture. Communication is a means by which this diffusion happens, often facilitating the spatial spread of ideas and technology. Therefore, the correct answer to the question is b) Movement and Human-Environment Interaction.
Human-Environment Interaction characterizes the reciprocal relationship between humans and the environment. It describes how human activities affect the environment and how environmental conditions, in turn, influence human choices and behaviors. The diffusion of culture is an example of this dynamic, as cultures adapt to and modify the environments they encounter.