The correct option is A Raichur Doab
One of the main aspects of the Vijayanagara Empire history, was the regular conflicts with the Bahmani rulers, primarily over the Raichur-Tungabhadra Doab region. It was a conflict, that often kept going back and forth, with the Vijayanagara rulers winning at times, and Bahmani Sultans the other times. The frequent conflicts with the Bahmani Sultans, had not just devastated large parts of the Doab area, but also resulted in wholesale massacres and destruction of temples too.