Answer :
I am pretty sure it is a. But the Indus valley writing was not discovered yet. They are still working on translating it
The correct answer is A.
The culture of the Indus Valley was a Bronze Age civilization, which developed from 3300 BC. C. to 1300 a. C. along the Indus River valley, in Afghanistan, Pakistan and northwestern India.
It depended on its river, the Indus overflowed every year, flooding large areas and depositing fertile sediments.
This immense agricultural potential was the basis on which urbanism was developed around the Indus River because of most of its population was engaged in the agriculture activity.