What could the people of indus valley have done to prevent the flooding that eventually forced them to abandon the cities

Explanation: Many Indus cities had been abandoned by 1900 BC. The Indus civilization collapsed due to the changes of the geography and climate of the area.  

The movement of the outer layer has caused the Indus river to flood and change its direction. The changes in the flow of river had brought a terrible effect on the main cities of Indus as they were connected with the river.

The drains became blocked as the overcrowded people stopped maintaining the drains. The Indus people could have shifted to a place with less scale floods.

d. the polar jet stream   lies between the polar easterlies and trade winds should be your answer

i honestly have no idea