In Gupta-period administration, the term 'Kayastha' primarily denoted which functionary?

This question belongs to the Gupta and post-Gupta phase, a period reconstructed through inscriptions, coins, monuments, literary works, scientific texts and accounts of foreign travellers. The Gupta age is often described as a classical or golden age because of important achievements in Sanskrit literature, temple architecture, sculpture, astronomy and mathematics, but the label should not conceal regional diversity or social and political change. A military commander, village headman and temple priest had different titles and functions in the administrative and religious structure. The stated answer is therefore correct because it satisfies the person, period, source and context together.