Which one of the following statements about Upanishads is not correct?

A Brihadaranayak and Chandogya Upanishads are in prose.

B Katha Upanishad is one of the earliest Upanishads.

C Upanishads proclaim salvation by knowledge rather than by faith.

D Upanishads do not consider a life of asceticism as absolutely necessary for salvation.