The most likely way Prince Shotoku would have brought aspects of Chinese culture to Japan is:
D. He sent scholars to China to learn about the culture directly and introduce aspects to Japan.
Prince Shotoku is known for his efforts to study and adopt Chinese culture, including Buddhism, Confucianism, and various administrative practices, and he did this by sending scholars and envoys to China. This direct interaction allowed Japan to assimilate Chinese ideas more effectively than relying solely on second-hand information.