The correct answer is: B) Kaveri (Cauvery)
The Kaveri River is the largest river in the Indian state of Karnataka. It is also the third-longest river in the Indian peninsula, after the Godavari and the Krishna rivers. The Kaveri River basin covers an area of about 81,000 square kilometers, which is about one-third of the area of Karnataka. The river originates in the Western Ghats mountains and flows through the states of Karnataka, Tamil Nadu, and Kerala. The Kaveri River is a major source of irrigation and drinking water for millions of people in the region. It is also a popular tourist destination, known for its scenic beauty and its many temples and historical sites.
The other options are incorrect because they are not the largest river basins in Karnataka. The Krishna River basin is the second-largest river basin in Karnataka, covering an area of about 65,000 square kilometers. The Godavari River basin is the third-largest river basin in Karnataka, covering an area of about 50,000 square kilometers. The Tungabhadra River basin is the fourth-largest river basin in Karnataka, covering an area of about 35,000 square kilometers.