Answer:
The answer is A. Indus River and floodplains of rich soil.
Step-by-step explanation:
The Harappan civilization, also known as the Indus Valley civilization, developed in the floodplains of the Indus River in what is now modern-day India and Pakistan. The Indus River provided water for irrigation, which allowed for the development of agriculture. The floodplains of the river were rich in nutrients and made for fertile land that was ideal for farming. The Harappans also had access to other natural resources such as timber, minerals, and stone, which contributed to their economic and technological development.