What was the most significant agricultural advantage of Champa rice for farmers in southern China?

It required significantly less water than other rice varieties.

It was naturally resistant to common pests, reducing crop loss.

Its fast-ripening nature allowed for the harvesting of two crops per year.

It produced a grain that was considered more flavorful and sold for a higher price.

The widespread cultivation of Champa rice was most effective in which part of China?

The mountainous western regions

A sharp decline in the overall population due to new diseases

A massive migration of people from cities to rural farming areas

A significant population explosion, pushing numbers over 100 million

A decrease in the average life expectancy