The most supported example of cultural diffusion depicted by the map is likely religion due to its widespread influence across various regions.
How to explain
Religion often diffuses and spreads through cultural interactions, transcending geographic boundaries. The map might illustrate religious symbols, temples, or sacred sites distributed widely, indicating the extensive reach and adoption of religious beliefs and practices.
Unlike other elements like philosophy or literature, which may have localized impacts, religion tends to traverse cultural barriers, leaving a more pronounced and pervasive mark on diverse societies, thus suggesting a stronger case for cultural diffusion in terms of religious influence.