The correct answer is (a) Rajendra Singh.
Rajendra Singh is an Indian environmentalist who has been working on water conservation and watershed management for over 30 years. He is the founder of the Tarun Bharat Sangh, a non-profit organization that works to protect water resources in India. Singh has been awarded the Stockholm Water Prize, the highest international award for water research and management, for his work on water conservation.
Sunita Narain is an Indian environmentalist and the director of the Centre for Science and Environment, a non-profit organization that works on environmental issues in India. She is a recipient of the Padma Shri, the fourth highest civilian award in India.
Sarabjit Singh is an Indian politician who is the current Chief Minister of Punjab. He is a member of the Shiromani Akali Dal political party.
Sunita Rani is an Indian athlete who specializes in the 100 metres and 200 metres events. She is a two-time gold medalist at the Asian Games.
Rajendra Singh is the most likely answer to the question because he is the only person on the list who has been awarded the Stockholm Water Prize. The Stockholm Water Prize is awarded to individuals or organizations who have made outstanding contributions to water research, management, and conservation. Rajendra Singh has been working on water conservation and watershed management for over 30 years, and he has made significant contributions to the field. He is the founder of the Tarun Bharat Sangh, a non-profit organization that works to protect water resources in India. Singh has also been a vocal advocate for water conservation and has worked to raise awareness of the importance of water resources.