Which of the above assumptions is/are valid?

Correct Option: (b) 2 only

Assumption 1: Invalid. The passage states 'If our cities were rich enough to meet the entire cost, water could be delivered free. They are not.' However, this does not mean *only* rich cities can ensure sustainable delivery; rather, cities need proper financing mechanisms (such as user charges or cost recovery) to achieve sustainability, even if they aren't inherently rich. Assumption 2: Valid. The passage explicitly elaborates that water delivery requires collecting from natural sources, treating it to make it potable, laying distribution networks, investing in sewerage infrastructure, and sewage treatment plants so that wastewater is not discharged untreated. This proves that sustainable delivery of water in cities means much more than simply supplying water to households. Thus, only assumption 2 is valid. Option (b) is correct.