Which are thought to have contributed to the decline of the Indus Valley civilization?



Choose all answers that are correct.


A.
Cities were destroyed by raging fires.


B.
Major sandstorms blanketed the cities, forcing people to leave.


C.
The soil became too salty for crops to grow.


D.
The Indus River and its tributaries changed course.


E.
People moved to more fertile regions of the subcontinent.