Option 1: The Prime Minister of India is the chairman of the National Water Resources Council. This means that the highest-ranking official in the country, who is currently Shri Narendra Modi, holds the position of chairman. The Prime Minister has the authority to lead and make decisions regarding the council`s activities.
Option 2: The Union Minister of Water Resources is not the correct answer. Although this position has a significant role in managing water resources at the national level, the chairman`s position is held by the Prime Minister and not the Union Minister of Water Resources.
Option 3: The Union Minister of Agriculture is also not the correct answer. While the Union Minister of Agriculture may have some involvement in water resource management, their role does not include chairing the National Water Resources Council.
Option 4: The Union Minister of Earth Sciences is not the correct answer either. The Union Minister of Earth Sciences is responsible for overseeing various aspects related to earth sciences, such as meteorology and seismology. Their role does not encompass chairing the National Water Resources Council.
In summary, the correct answer is option 1, the Prime Minister of India.