Rigveda is the oldest of the four Vedas, the sacred texts of Hinduism. It is a collection of hymns and prayers dedicated to various gods and goddesses.

Vyasa is the traditional author of the Mahabharata, one of the two major Sanskrit epics of ancient India.

Ravana is a character from the Ramayana, but he is not a character from the Mahabharata.

Atharvaveda is considered as the fifth Veda, and it is a collection of hymns, spells, and charms.

Mahavira is considered as the founder of Jainism, and he is also known as Vardhamana.

Caste system is not a principle of Jainism, as Jainism rejects the idea of caste distinctions.

Buddha is considered as the founder of Buddhism, and he is also known as Siddhartha Gautama.

Caste system is not a principle of Buddhism, as Buddhism rejects the idea of caste distinctions.

Bhagavad Gita is a sacred text of Hinduism, not Sikhism.

Guru Nanak is considered as the founder of Sikhism, and he is also known as the first Guru.

Caste system is not a principle of Sikhism, as Sikhism rejects the idea of caste distinctions.

Quran is a sacred text of Islam, not Hinduism.

Hinduism does not have a single founder, as it is a collection of diverse beliefs and practices.

Caste system is not a principle of Hinduism, as Hinduism rejects the idea of caste distinctions.

Vedas are sacred texts of Hinduism, not Islam.