Final answer:
Hierarchical diffusion follows an ordered sequence often from authoritative figures or larger to smaller areas, whereas contagious diffusion spreads rapidly and evenly across populations without following any specific hierarchical order.
Step-by-step explanation:
The main difference between Hierarchical diffusion and Contagious diffusion is related to their patterns and spread mechanisms. Hierarchical diffusion occurs when ideas or diseases spread through an ordered sequence, often progressing from larger to smaller places, or from higher authority to the general population, as seen when rulers adopt a religion and then it spreads down through the levels of society. In contrast, contagious diffusion happens when something spreads uniformly and indiscriminately across populations, similar to the rapid and uncontrolled spread of a disease amongst individuals, without following a hierarchical pattern.
To choose the correct option from the student's question, we apply this understanding. Hierarchical diffusion does occur through a specific order or hierarchy, often starting with people or places of influence and then trickling down or out to others. On the other hand, contagious diffusion spreads evenly and rapidly among individuals without any structured order, just like a virus would spread in a population. Therefore, the correct choice aligns with this distinction.