What can be best inferred from this passage about the progress made under Gupta rule?
A.The unified government under the Guptas caused India to be politically united.
B.The Guptas maintained good relations with the outside world to improve trade.
C.The open-minded attitude of the Guptas facilitated advances in fields such as art, literature, and architecture.
D.The Guptas encouraged all religions in order to establish the security of the people.