The correct answer is (d). The Aachiketa legend finds mention in the Brihadaranyaka Upanishad.
The Brihadaranyaka Upanishad is one of the most important Upanishads, a collection of Hindu scriptures that form part of the Vedanta school of philosophy. The Upanishads are considered to be the culmination of the Vedas, the oldest scriptures of Hinduism.
The Aachiketa legend is a story about a young man named Nachiketa who goes to the god Yama, the god of death, to ask him a question. Nachiketa asks Yama what happens to a person after they die. Yama is impressed by Nachiketa’s courage and intelligence, and he answers his question.
The Aachiketa legend is a story about the importance of seeking knowledge and understanding. It is also a story about the importance of courage and determination.
The other options are incorrect. The Atharva Veda is a collection of Vedic hymns. The Satapatha Brahmana is a Brahmana, a type of Vedic text that is a commentary on the Vedas. The Kathopanishad is an Upanishad that is part of the Yajur Veda.