The correct option is B Attack of combined armies of Bijapur,Golconda and Ahmednagar .
Battle of Talikota in 1565 considered as the major downfall of the Vijayanagar Empire. The combined armies of Deccan Sultanates, that is, Bijapur, Golconda and Ahmednagar attacked the Vijayanagara kingdom and defeated the army of Vijayanagar King Rama Raya and killed him during the war.