A single narrative detailing one of Buddha's former existences is known by which of the following names?

The correct option is Jataka.

Explanation:

Jataka tales are a voluminous body of literature native to India concerning the previous births of Gautama Buddha. These stories detail the former existences of the Buddha (in both human and animal form), demonstrating virtues such as compassion, wisdom, and self-sacrifice.

Let us briefly review the other terms mentioned in the options to understand why they differ:

• Vinaya: Refers to the Vinaya Pitaka, which contains the rules and regulations for the Buddhist monastic order (Sangha).
• Tripitaka: Means "Three Baskets", representing the traditional term for the Buddhist scriptures comprising the Vinaya Pitaka, Sutta Pitaka, and Abhidhamma Pitaka.
• Sutra: Refers to canonical scriptures recording the oral teachings and discourses of Gautama Buddha.