The correct answer is (a) Arbitration.
Arbitration is a method of settling disputes between two or more parties by referring them to an independent third party, the arbitrator, who renders a binding decision. The Constitution of India expressly recognizes arbitration as a method of settling international disputes in Article 32(1), which provides that “the Supreme Court shall have jurisdiction to hear, inter alia, any dispute with respect to any treaty or agreement between the Government of India and any other country.”
Negotiation is a process of discussion and compromise between two or more parties with the aim of reaching an agreement. Conciliation is a process of mediation in which a neutral third party helps the parties to reach an agreement. Both negotiation and conciliation are voluntary processes, and the parties are free to accept or reject the recommendations of the mediator or conciliator.
The Constitution of India does not expressly recognize negotiation or conciliation as methods of settling international disputes. However, these methods are often used in practice, and they may be referred to in treaties or agreements between India and other countries.