The correct option is C Inscriptions of Ashoka
Inscriptions of Ashoka are considered as the single most important source of the history of Ashoka. Ashokan edicts are basically of three types, i.e. rock edicts (major rock edicts and minor rock edicts), pillar edicts and cave inscriptions. Ashokan inscriptions were written in Pali language and the script was Brahmi. But two major rock edicts at Mansehra and Shahbajgarhi were inscribed in Kharosthi script.