Define the term "cultural diffusion."

Cultural diffusion is defined as the spread of cultural beliefs, practices, and items from one group to another. This phenomenon occurs when different societies come into contact and exchange ideas, customs, and technologies. Factors that facilitate cultural diffusion include trade, migration, and conquest, which allow for the sharing of cultural practices across geographical and social boundaries.

The correct choice highlights the essence of cultural diffusion as a process of cultural exchange and adaptation, showcasing how cultures evolve and influence one another over time. This interaction enriches societies by introducing new perspectives and practices, enabling cultural growth and transformation.

In contrast, the other options do not accurately capture the definition of cultural diffusion. The incorporation of new technology into a culture pertains more to innovation and adaptation within a specific culture rather than the spreading of culture. Isolation of cultural groups refers to the opposite of diffusion, as it entails limited to no exchange with other cultures. The formation of unique subcultures recognizes the development of distinct cultural identities within a larger society, but it does not emphasize the interaction and exchange between different cultures which is central to the concept of cultural diffusion.