- Emigration is the act of leaving one's country of origin to reside permanently in another; it does not denote cultural borrowing.
- Diffusion is the appropriate term for the transmission of cultural elements, such as ideas, practices, or technologies, from one society to another.
- Degeneration signifies a decline or deterioration, commonly applied to health or societal conditions, not the adoption of cultural traits.
- Innovation involves the generation of novel concepts, practices, or objects, distinct from the adoption of existing cultural elements.
Step 1: Comprehending Diffusion.
Cultural diffusion transpires when cultural components, like cuisine, faith, or technological advancements, are exchanged among disparate societies via commerce, populace movement, or discourse.
Final Answer:
\[\boxed{\text{The correct answer is (2) Diffusion.}}\]