Answer:
The answer is the option D. ( the Ly dynasty)
Explanation: Buddhism came to Vietnam approximately 2nd or 3rd BCE from the Indian Sub continent or by the China on 1st or 2nd BCE. However Buddhism became a practicing religion in Vietnam. But it came to it's zenith during the Ly dynasty. During this dynasty Buddhism became the state recognized belief. All of the kings of LY dynasty sanctioned Buddhism as the state religion of Vietnam.
