The correct options are
A Building of dams
C Building of embankments
The Chinese civilisation emerged in the region of the river Hwang-Ho. The river often changed its course, destroyed settlements and drowned people. As a result, Hwang-Ho was known as the ‘Sorrow of China. By building dykes and embankments the ancient Chinese were able to reduce the damage caused by floods. This in turn led to the growth of the ancient Chinese civilisation.