Which of the following statements about the Upanishads is TRUE?
a. They are a body of works that seek to probe the inner meaning of the earlier Vedas.
b. They put a priority on introspection instead of external ritual.
c. They were a response to discontent, as the Brahmins claimed too much wealth and privilege through their control of Vedic rituals.
d. All of the above.
Answer: D