Answer:
B.fertile soil and fresh water of the Indus River Valley.
Explanation:
The culture of the Indus Valley was a civilization of the Bronze Age, which developed from around 3300 BC. C. to 1300 a. C. along the Indus River valley, in Afghanistan, Pakistan and northwestern India. It encompassed about a hundred settlements and two major cities: Harappa and Mohenjo-Daro, both sites in Pakistan. Altogether it comprised the most extensive area of all the ancient civilizations, more than a million square kilometers, and it crossed several periods, being its maximum splendor between the 2600 and the 1900 a. C.
Like the civilizations of Mesopotamia and Egypt, it depended on its river. Like the Nile, the Indus overflowed every year, flooding large areas and depositing fertile sediments. This immense agricultural potential was the basis on which urbanism developed around the Indus River.
With the prehistoric cultures of the Indus Valley the first chapter of the history of India is prepared. It is a long prehistoric period, proven by lithic testimonies. On the other hand, you can find prehistoric vestiges until the 1st millennium BC. C., that is, until a time when the peninsula had already entered history. Strictly speaking, the cultures of the Indus belong to prehistory since they have left only archaeological remains without literary documents, but to appreciate Indian history it is necessary to take into consideration these pre-urban urban cultures.
