Which of the following describes a positivist account of law?

Kelsen's pure theory of law, a leading positivist account, holds that a legal norm is valid because it derives from a higher norm, in a chain that ends in the "grundnorm" or basic norm, and not because of its moral content. Treating natural and positive law as one, or making validity depend on morality or popular conviction, belongs to natural law or historical thinking, not positivism.