Which is the oldest Buddhist literature?

Option 1 : Tripitaka

The correct answer is Tripitaka. 

Explanation

Tripitaka

• Tripitaka is the traditional term for the Buddhist scriptures in the Theravadan Buddhist tradition.
• The teachings are contained in three volumes:
  • The Vinaya Pitaka: primary subject matter is the monastic rules for monks and nuns.
  • The Sutta Pitaka: contains more than 10,000 suttas (teachings) attributed to the Buddha or his close companions.
  • The Abhidhamma Piṭaka:  It is a detailed scholastic analysis and summary of the Buddha's teachings in the Suttas.

Deepvamsha

• The oldest historical record of Sri Lanka, compiled in the 4th century.
• It is a crude, unpolished perhaps the first attempt to write in the Pali language. 
• In its emphasis on Buddhist rather than political history and in the time span of its narrative.

Mahavansha

• It is the chronological history of Ceylon aka modern Sri Lanka.
• Written in the 5th or 6th century, probably by the Buddhist monk Mahanama.
• It deals with the history of Buddhism and with the dynastic succession of Ceylon and covers the period from 6th century BC to the 4th century AD.

Milind Panho

• It is a lively dialogue on Buddhist doctrine with questions and dilemmas asked by King Milinda aka Menander and answered by Nagasena, a senior monk.
• Composed in Northern India in the 1st or 2nd century by an unknown author.