Final answer:
The best description of the relationship between the spread of Buddhism and the statues is that the statues indicate Buddhism's widespread adoption across Asia.
Step-by-step explanation:
The relationship between the spread of Buddhism and the statues is best described by option D: The statues show that Buddhism was adopted by people throughout Asia. The huge statues of Buddha carved along the Silk Roads demonstrate the importance of trade routes in the spread of culture and ideas, including the diffusion of Buddhism. Buddhism's spread was facilitated by a combination of trade, the patronage of Buddhist art and architecture by monarchs like King Ashoka, and the transformation and adaptation of Buddhist teachings and practices to fit local cultural contexts. As a result, Buddhism attracted a wide range of followers from different social classes across Asia, profoundly influencing art, culture, and society.