There is a very important word in the topic of "Southern and Northern Dynasties", which highlights the test point of this topic, that is, the development of Jiangnan area (during the Wei, Jin and Southern and Northern Dynasties, due to the war in the north, a large number of people moved south, which promoted the economic development of Jiangnan area, which was the first large-scale population migration south in Chinese history. )

So looking back at the answer, A said that the economic level of the Yangtze River basin is higher than that of the Yellow River basin. The development of the Yangtze River basin is caused by the population migration in the Yellow River basin, which proves that the economic level of the Yellow River basin is higher.

B Hexi Corridor and Lingnan are really not the fastest, but the fastest is the Yangtze River basin (the fastest, not necessarily the highest), thanks to those who moved south.

According to historical judgment, the silk industry is not the best developed in the Yellow River Basin, and only rare products are qualified to serve as currency.

D because of economic stability, money will be produced, and if there is chaos, gold and silver will be regarded as rare products (just like in the Republic of China, when gold certificates depreciated, everyone exchanged gold and silver because they could preserve their value)

I hope I can help LL~