The correct answer is: C. Only 1 & 3
Mekedatu river project is disputed between Karnataka and Tamil Nadu. Mahadayi water dispute is between Karnataka and Goa. Vansadhara river dispute is between Odisha and Andhra Pradesh.
The Mekedatu project is a proposed dam on the Cauvery River in Karnataka. The project has been opposed by Tamil Nadu, which claims that it will reduce the water flow into the state. The dispute has been going on for several years, and has been the subject of several court cases.
The Mahadayi water dispute is a dispute between Karnataka and Goa over the sharing of water from the Mahadayi River. The dispute has been going on for several years, and has been the subject of several court cases.
The Vansadhara river dispute is a dispute between Odisha and Andhra Pradesh over the sharing of water from the Vansadhara River. The dispute has been going on for several years, and has been the subject of several court cases.