The correct answer is option 2, the Battle of Talikota. This battle led to the downfall of the Vijayanagar empire. The Battle of Talikota took place in 1565 between the Vijayanagar empire and the Deccan Sultanates. The Deccan Sultanates formed an alliance and launched an attack on Vijayanagar. Despite the numerical advantage, the Vijayanagar forces were defeated and the city of Vijayanagar was pillaged and destroyed. This battle marked a turning point in the history of the Vijayanagar empire. It weakened their power and control over the region, leading to a decline that ultimately resulted in the downfall of the empire. The battle was significant in altering the political landscape of South India.