Q. Sarnath, is related to which among the following events in the life of Buddha?
Answer: First Sermon
Notes: The deer park in Sarnath is where Gautama Buddha first taught the Dharma, and where the Buddhist Sangha came into existence through the enlightenment of Kondanna. It was also the site of the Buddha's Dhammacakkappavattana Sutta, which was his first teaching after attaining enlightenment, in which he taught the four noble truths and the teachings associated with it.
So either A or D can be marked as the correct answer.