Final answer:
The incorrect statement about the Harappan culture is that it marked the earliest known use of iron for sculpting; iron was not used by the Harappans for this purpose. The correct answer is option (c).
Step-by-step explanation:
The statement about the Harappan culture that is not correct is (c) it marks the earliest known use of iron as a medium for the art of sculpting. The Harappan culture, part of the ancient Indus Valley Civilization, is renowned for its advancements in urban planning, architecture, and a mysterious script that remains undeciphered. It did not, however, use iron in sculpting; its material of choice was mostly stone and other metals, but iron was not used until later cultural periods in the region. Some aspects of their urban civilization included detailed drainage systems and orderly streets, as well as the use of oven-fired bricks for construction. The Indus script was written from right to left, marking the first use of script in the subcontinent. Furthermore, evidence of trade with Mesopotamia suggests cultural exchanges that influenced the art and culture of the Harappan people.