Explanation:

• The Mahadayi Water Disputes Tribunal (MWDT), is a tribunal that adjudicates the dispute over River Mhadei water allocation. The sharing of the waters of this river is a cause of dispute between the governments of Karnataka and Goa
• It originates in the Belagavi district of Karnataka, briefly passes through Maharashtra and flows through Goa (where its known as Mandovi), and drains to the Arabian Sea.
• Since the eighties, Karnataka has been was contemplating linking of Mahadayi with Malaprabha river, a tributary of Krishna.
• In 2002, Karnataka gave the idea a shape in the form of the Kalasa-Bhanduri project.
• Goa strongly opposed it as Mahadayi is one of the two rivers the State is dependent on and thus Mahadayi Water Disputes Tribunal was set up in 2010.

Hence option 1st is correct.