Correct Option: B

The Third Buddhist council was convened in about 250 BCE at Asokarama in Pataliputra, supposedly under the patronage of Emperor Asoka. It was presided over by the Elder Moggaliputta Tissa and one thousand monks participated in the Council. The council is recognized and known to both the Theravada and Mahayana schools, though its importance is central only to the Theravada school.