The correct option is 2 and 3 only
Explanation
Chanhudaro is a significant site of the Indus Valley Civilization, distinguished not by its size but by its intensive industrial activity. It serves as a primary example of a specialized craft production centre within the Harappan urban network.
Statement 1 is Incorrect:
Chanhudaro was a small settlement (approximately 7 hectares) compared to major cities like Mohenjodaro (125 hectares). However, it was almost exclusively devoted to craft production rather than being solely a trading centre. The production activities included bead-making, shell-cutting, metal-working, seal-making, and weight-making.
Statement 2 is Correct:
Archaeological excavations have yielded tools indicating high technological specialization. Specialized drills have been found at Chanhudaro, Lothal, and Dholavira. These drills were crucial for boring holes in hard stones to create the beads for which the civilization is famous.
Statement 3 is Correct:
The Harappans utilized pyrotechnology to alter the properties of stones. The characteristic red colour of carnelian was obtained by firing the yellowish raw material and beads at various stages of production. This heat treatment improved the flaking quality of the stone and enhanced its colour.
Key Takeaway:
Chanhudaro is the quintessential "factory site" of the Indus Valley Civilization, characterized by specialized craft industries, particularly bead-making using drills and chemical alteration of stones (carnelian) through firing.