TOEFL Listening: TPO-TOEFL阅读TPO - 551752G336SO5YV0N$

What purpose does paragraph 5 serve in the larger discussion about China's population growth? A. It provides evidence of China's emerging foreign trade relations. B. It illustrates how the Chinese increased their food supply. C. It provides evidence of why population growth was most noticeable in the south. D. It shows how foreign crops gradually gained greater acceptance in China.