Option a is the correct answer. Allahabad Prashasti is an inscription on an Ashokan pillar that contains the eulogy of the Gupta ruler Samudragupta, composed by his court poet Harisena. The inscription describes the political and military achievements of Samudragupta, as well as his personal qualities and religious beliefs. It clearly presents the Gupta empire as the epicenter of a complex web of varied political relationships. The inscription mentions four types of rulers who had different kinds of relations with Samudragupta: those who were uprooted and exterminated; those who surrendered and paid tribute; those who sought his protection and alliance; and those who were on the frontiers and acknowledged his suzerainty.