With steady economic growth, higher literacy and increasing skill levels, the number of Indian middle- class families has gone up exponentially. Direct results of the affluence have been changes in dietary patterns and energy consumption levels. People have moved to a higher protein- based diet like milk products, fish and meat, all of which need significantly more water to produce than cereal- based diets. Increasing use of electronic and electric machines/gadgets and motor vehicles needs more and more energy and generation of energy needs water. Which one of the following statements best reflects the crux of the passage?

The passage describes how economic growth and affluence lead to changes in dietary patterns (higher protein, needing more water) and energy consumption (more electronics/vehicles, needing water for generation). The common thread and the central problem highlighted throughout the passage is the significantly increased demand for water due to these lifestyle changes.

Let's analyze the options:

A) People should be persuaded to continue with the mainly Indian traditional cereal-based diets - This is a prescriptive suggestion focusing only on diet and doesn't capture the broader issue of energy consumption or the overall implication of increased water demand. The passage describes a change, not necessarily advocates for reversing it.

B) India needs to focus on developing agricultural productivity and capacity for more energy generation in the coming years - While these are mentioned as areas of consumption, the passage specifically points out that these activities (in their new forms) need more water. Simply increasing productivity or capacity without addressing the water cost misses the core concern raised.

C) Modern technological developments result in the change of cultural and social behaviour of the people - This is a general statement that describes a part of the premise (people moving to higher protein diets, using more gadgets). However, it doesn't reflect the consequence or the problem that the passage builds up to, which is the escalating demand for water.

D) Water management practices in India need to change dramatically in the coming years - The passage repeatedly emphasizes that both the new dietary patterns and increased energy generation "need significantly more water." The exponential increase in demand for water due to these changes implies that current water management practices will be insufficient, thus necessitating dramatic changes. This option best reflects the core implication and challenge presented by the passage.

The final answer is D