Find out the correct statement.
(a) The introduction of Bronze tools made easy the removal of dense forest cover from the banks of the Ganges.
(b) Ajivikas had a small presence in western India.
(c) The clusters where particular clansmen were dominant came to be known were Pre-Maury an states.
(d) Of the kingdoms mentioned in the literature .of the period Kashi, Kosala and Magadha are considered to be powerful.