Buddhism Was Not Always Easy to Introduce into Some Areas

Buddhism was not always easy to introduce into some areas of Korea.By what process did the area of Silla adopt Buddhism?

A) Conquest by a rival Buddhist kingdom.
B) Marriage to a Buddhist princess.
C) Buddhist monks able to convert most of the royal families.
D) By the immigration of Chinese fleeing the turmoil of the Tang era.
E) Through a Buddhist miracle.