Answer:
b. rice, soybeans, and walnuts were first domesticated in East Asia.
Step-by-step explanation:
These are some of the crops that were first domesticated in East Asia. East Asia is a subregion of the Asian continent, which consists of countries such as China, Hong Kong, Macao, Mongolia, North Korea, South Korea, Japan and Taiwan. Two of these crops (rice and soybeans) continue to be a staple in the region, while all of these have become common all over the world.