During the period of the Three Kingdoms in Korea, Chinese influence was spread through multiple avenues. However, among the options provided, the most significant methods included:
a. Through the travels of Chinese Buddhist monks - Buddhism was introduced to Korea from China during this period, leading to profound cultural and spiritual influence.
c. Through the introduction of Chinese art and technology - The Three Kingdoms adopted various aspects of Chinese culture, including art styles, methods of governance, and agricultural techniques.
d. Through the Chinese writing system - The adoption of Classical Chinese as a written language had a lasting impact on Korean literacy and literature.
While military conquest also played a role in the influence of China on Korea, the cultural aspects are more directly linked to the influence of China during the Three Kingdoms period.
In summary, the spread of Chinese influence in Korea during this time was primarily through cultural exchanges involving Buddhism, art, technology, and the writing system. So the correct answers among your options would be: a, c, and d.