The concept of Eight-fold path forms the theme of:

Correct Option

The Eight-fold Path constitutes the central theme of the Dharma Chakra Pravartana Sutta (Setting in Motion the Wheel of Dharma), which was the Buddha's first sermon delivered at Sarnath. This path is presented as the means to attain Nirvana, encompassing principles of ethical conduct (Sila), mental discipline (Samadhi), and wisdom (Prajna). The eight components are:

• Right Understanding (Samma Ditthi)
• Right Thought (Samma Sankappa)
• Right Speech (Samma Vaca)
• Right Action (Samma Kammanta)
• Right Livelihood (Samma Ajiva)
• Right Effort (Samma Vayama)
• Right Mindfulness (Samma Sati)
• Right Concentration (Samma Samadhi)

Incorrect Options

Option (A) Dipavamsa: It is an ancient chronicle of Sri Lanka, primarily focusing on the history of Buddhism on the island. It does not elaborate on the Eight-fold Path as its central theme.

Option (B) Divyavadana: This is a collection of Buddhist narratives and legends, often illustrating the karmic consequences of actions. It is not dedicated to expounding the Eight-fold Path.

Option (C) Mahaparinibban: This refers to the Mahaparinibbana Sutta, which describes the final days, death, and cremation of Gautama Buddha, along with his last teachings. While it contains various teachings, the Eight-fold Path is not its exclusive or primary theme.