Explanation:

During the times of Buddha, the king of Avanti was Chandpajjota. He sent his son Mahakacchana, along with seven others to invite Buddha to Avanti. Buddha preaches them and all of them attain arhatship.Kosala and Magadha were linked through matrimonial ties. Buddha wandered through the towns and villages in the kingdoms of Kosala and Magadha teaching his philosophy. Gandhara is not directly associated with the life of Buddha. It was expansion of Maurya empire that Gandhara received much Buddhist influence, notably during the reign of Asoka.