Which statement best differentiates contagious diffusion from hierarchical diffusion?

• A. Contagious diffusion spreads through proximity from person to person, but only within the same city.
• B. Hierarchical diffusion spreads via random relocation of populations.
• C. Contagious diffusion is the same as relocation diffusion.
• D. Contagious diffusion spreads through proximity from person to person; hierarchical diffusion spreads via an ordered sequence of places from larger to smaller places.

Answer: (D)

Contagious diffusion describes how something spreads through close contact and proximity, moving from person to person and often crossing into nearby areas quickly. Hierarchical diffusion works through an ordered sequence of places, typically moving from larger or more influential locations to smaller or less influential ones, following the urban or organizational hierarchy. The statement that best captures both ideas says contagious diffusion spreads by proximity from person to person, while hierarchical diffusion spreads via an ordered sequence of places from larger to smaller places. For example, a new fashion trend might emerge in a major city and quickly reach nearby towns (contagious), whereas a technology or idea could spread from a capital city to regional centers and then to smaller towns in a stepwise fashion (hierarchical). The other options misstate the mechanisms: contagious diffusion is not limited to one city; hierarchical diffusion is not about random relocation; contagious diffusion is not the same as relocation diffusion.