Option d is the correct answer The Upanishads are late Vedic Sanskrit texts of Hindu philosophy which form the foundations of Hinduism. The Upanishads are philosophical texts dealing with topics like the soul, the absolute, the origin of the world and the mysteries of nature. Important Tips Upanishads It criticizes the rituals and lay stress on the value of right belief and knowledge. The language of the Upanishads was classical Sanskrit and not the Vedic Sanskrit. The Upanishads are often called 'Vedanta'. Literally, Vedanta means the end of Veda, Vedasya antah, the conclusion (Anta) as well as the goal (Anta) of the Vedas. Chronologically they came at the end of the Vedic period.