Provisions relating to fundamental duties cannot be enforced by writs. They can be only promoted by constitutional methods. But they can be used for interpreting ambiguous statutes'. In which of the cases was this principle enunciated -

A. Motilal v. State of UP

B. Civil Rights Committee v. UOI

C. Head Masters v. UOI

D. Magan Bhai v. UOI

Answer: Option C