Correct Option: B

According to the scriptures of all Buddhist schools, the first Buddhist Council was held soon after the Mahaparinirvana of the Buddha, dated by the majority of recent scholars around 400 BCE, under the patronage of king Ajatasatru with the monk Mahakasyapa presiding, at Sattapanni caves Rajgriha. Its objective was to preserve the Buddha's sayings and the monastic discipline or rules (Vinaya).