Question

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

Choose all answers that are correct.

A.
Volcanic eruptions covered the land with molten lava.

B.
The surrounding land was severely deforested.

C.
Centuries of floods made the soil salty and unfit for farming.

D.
Diseases reduced the population.

E.
Indus Valley populations migrated to Central Asia and Africa.