01 What was the probable purpose of placing the smooth surfaces of bricks toward the inside of Harappan drains?
Answer and explanation
Correct answer: A. To maintain smooth water flow and reduce seepage
Explanation: The governing concept is functional interpretation of construction details. Turning smoother brick faces toward the channel would reduce roughness along the inner wall and could help wastewater flow more easily; careful fitting could also limit leakage through joints. This feature is therefore better explained by drainage efficiency than by decoration. It would not deliberately narrow the channel or stop all waste, since drains were designed to carry away water and refuse. Option A is correct.