Answer: B. Paid Buddhist monks spreading teachings and conversion
Step-by-step explanation:
Even though the Gupta emperors encouraged religious freedom and so had no problem with Buddhism and Jainism spreading, it is very unlikely that they actually paid Buddhist monks to try to convert people to Buddhism.
This is because the Gupta emperors were Hindu so it would make little sense that they would pay someone to convert people from their religion. It was Ashoka the Great of the Maurya Dynasty that was an ardent enough supporter of Buddhism to do this.