The concept of the Eight-fold Path forms the theme of the Dharma Chakara Pravartana Sutta.

Explanation:

The Eight-fold Path is a central concept in Buddhism and is one of the core teachings of the Buddha. It is a path that leads to the cessation of suffering and the attainment of enlightenment. The Eight-fold Path consists of eight interconnected principles or practices that are meant to be followed by Buddhist practitioners.

The Dharma Chakara Pravartana Sutta, also known as the Dhammacakkappavattana Sutta or the "Setting in Motion the Wheel of Dharma," is a discourse given by the Buddha after his enlightenment. It is considered one of the most important and foundational teachings of Buddhism. In this sutta, the Buddha explains the Four Noble Truths and introduces the Eight-fold Path as the way to overcome suffering and achieve liberation.

Therefore, the correct answer is Dharma Chakara Pravartana Sutta.