Church Takes a Principled Stand Against Conflict

The correct answer is:

c. principled

The sentence should be: 'The Church is taking a principled stand against the conflict.'

'Principle' is a noun referring to a fundamental truth or belief, while 'principles' is the plural form of the noun. In this sentence, we are describing the stand being taken by the Church as being based on principles, so the correct form to use is the adjective 'principled'.