Statement & Argument — Should rooftop rainwater harvesting be mandatory for every builder in the city? Arguments: I. Yes, a 100 sq m roof in Delhi can capture and recharge about 65,000 liters, meeting domestic needs of a family of four for roughly 160 days. II. Yes, groundwater levels are falling by about 1 metre per year in some areas, compounding water crisis.

Introduction / Context:
Urban water sustainability policies rely on demand management and local recharge. Quantified benefits and crisis indicators both support mandates.

Given Data / Assumptions:

• Significant rooftop harvesting yields are possible in many Indian cities.
• Groundwater depletion is a serious, documented issue.

Concept / Approach:
Argument I is strong as it provides quantification of benefit. Argument II is strong as it shows urgency. As both are independently compelling and in the same direction, either argument is strong is the accepted test option.

Final Answer:
Either Argument I or II is strong.