The correct option is A Because he freed Mahmud Shah.
Gulbarga region was under the rule of Yusuf Adil Shah who had imprisoned the Bahmani sultan, Mahmud Shah. Krishnadevaraya defeated Adil Shah and freed Mahmud Shah, restoring his position as Sultan. For this, Krishnadevaraya was given the title 'Yavana Rajya Prathishtapanacharya'.