Analyze each option in the context of the passage.
Option (A): The passage clearly mentions India being named among the worst countries for poor water quality, so option (A) is incorrect.
Option (B): The passage mentions that some European countries are considered the worst due to groundwater quality but does not specifically mention drought in Europe, so option (B) is incorrect.
Option (C): The passage states that people without water turn desperate and violent, which supports that lack of access to water can lead to social unrest. Thus, option (C) is correct.
Option (D): The passage mentions the severe droughts in Rajasthan, Madhya Pradesh, and Andhra Pradesh, clearly showing the intense shortage of water in some states of India, so option (D) is correct.
Thus, the correct statements are (C) and (D).