Respuesta :

I believe it would be 5

Answer:

D) 5

Explanation:

The Yangtze River starts by the Tibetan Plateau and flows 6,300 km until its end at the East China Sea. Archaeological discoveries show that the Yangtze Valley civilization lasted for about 500 years. Urban centres and 13 walled towns and cities dating from around 3000BC have been found. Their civilization collapsed due to climatic and environmental problems and warfare.