Which two developments in ancient and medieval japan reflect the influence of korea and china? 1) wet rice agriculture 2) shinto shrines 3) zen buddhism 4) the rule of the yamato clan 5) the rise of the samurai class

1) wet rice agriculture 
3) Zen Buddhism

Wet rice agriculture and Zen Buddhism are two development in ancient and medieval Japan reflect the influence of Korea and China. Both practices were born and developed outside of Japan, but they were brought in by travellers and scholars alike. They become popular in Japan and they remain a stable until the industrial revolution.

It was so significant because It has basically left its scar on europe, killing millions and spreading through the nation! thats why. =)