Q. Which Upanishad mentions the well-known dialogue between Nachiketa and Yama? Answer:
Mundkopanishad
Notes: The conversation between Nachiketa and Yama (Lord of death) is mentioned in Kathopanishad (5th century BC), also known as Katha Upanishad. He was taught self-knowledge, the separation of the human soul (the supreme Self) from the body, by Yama.