The Cauvery water dispute is a long-standing issue between Tamil Nadu and:

Andhra Pradesh
Karnataka
Kerala
Telangana

The correct answer is: b) Karnataka.

The Cauvery water dispute is a long-standing issue between Tamil Nadu and Karnataka over the sharing of water from the Cauvery River. The river originates in the Western Ghats in Karnataka and flows through Tamil Nadu and Kerala before emptying into the Bay of Bengal. The dispute has its roots in the British colonial era, when the Madras Presidency (now Tamil Nadu) and the Mysore State (now Karnataka) were under British rule. The British government established a water-sharing agreement between the two states in 1892, but this agreement has been the subject of dispute ever since.

The dispute has intensified in recent years due to the increasing demand for water for irrigation and drinking purposes in both Tamil Nadu and Karnataka. In 2016, the Supreme Court of India ruled that Karnataka should release 192 tmcft of water to Tamil Nadu every year. However, Karnataka has refused to comply with the order, arguing that it does not have enough water to meet its own needs.

The Cauvery water dispute has had a significant impact on the lives of people in both Tamil Nadu and Karnataka. The dispute has led to protests, violence, and even death. It has also hampered economic development in both states.

The Cauvery water dispute is a complex and intractable issue. There is no easy solution to the dispute, and it is likely to continue to be a source of tension between Tamil Nadu and Karnataka for many years to come.

The other options are incorrect because they are not the states that are involved in the Cauvery water dispute. Andhra Pradesh, Kerala, and Telangana are not involved in the dispute.