Which of the following literature is preserved by oral tradition?
A. Vedic
B. Buddhist
C. Jain
D. All of the above.

Hint: Oral tradition is one of the most widespread modes of communication between human beings. The art, ideas, culture are transmitted from one person to another, and from one generation to another. Oral traditions represent a multifunctional means of verbal communication that supports diverse activities of a different culture.

Complete Answer:
The transmission of old stories, legends just as sacred writings in antiquated India, in various Indian religions, was by oral convention, safeguarded with exactness with the assistance of expanding memory aid techniques. The early Buddhist writings are additionally commonly accepted to be of oral custom, with the first by looking at irregularities in the sent renditions of writing from different oral social orders, for example, the Greek, Serbia and different societies, at that point noticing that the Vedic writing is excessively steady and immense to have been created and communicated orally across ages, without being composed down. According to Goody, the Vedic messages probably elaborate both a composed and oral convention, considering it an "equal results of a proficient society"
So, the correct answer is Option D.

Note: The different types of literature whether Vedic or Buddhist is available now in written and oral form as well. The mode of communication has been changed with time but the relevance of the oral tradition is still there in India. Except for India, in other parts of the world, oral traditions have been believed significant since ancient times. So throughout the world, literature had been preserved by oral traditions.