Which one of the following organizations believes in Upanishads?

Brahmo Samaj, founded by Raja Ram Mohan Roy in 1828, believed in the Upanishads and the Vedas as the foundation of true Hinduism. It rejected idolatry, polytheism, and rituals, advocating monotheism based on Upanishadic philosophy. Roy translated several Upanishads into Bengali and English to spread their monotheistic message. While other reform movements had their own focuses, Brahmo Samaj is most directly associated with Upanishadic belief.