Correct option is C
The right answer is (c) After going enlightenment, Lord Buddha delivered his first sermon in Sarnath.
The phrase "Dharmachakra Pravartana" alludes to the "Turning of the Wheel of Dharma" and describes Lord Buddha's first sermon following enlightenment. He gave this discourse in Sarnath, near Varanasi, to his first five disciples, teaching them the Four Noble Truths and the Eightfold Path. This event represents the beginning of Buddhism's spread.