The Nagarjuna Sagar project is constructed on the Krishna River. The other options, namely the Sutlej, Jhelam, and Narmada rivers, are not correct. The Sutlej River is a tributary of the Indus River located in northern India and Pakistan. The Jhelam River is also a tributary of the Indus River and flows through India and Pakistan. The Narmada River is one of the major rivers in central India, but it is not associated with the Nagarjuna Sagar project. Therefore, the correct answer is option 4, Krishna. The project is located in the state of Telangana, India, and is one of the largest irrigation projects in the world, providing water for irrigation and power generation.