HANS KELSEN's PURE THEORY OF LAW (1934) advances:

1. HANS KELSEN (1881-1973) advanced the PURE THEORY OF LAW (Reine Rechtslehre) — first published 1934, expanded edition 1960. 2. Kelsen sought to PURIFY legal theory from extraneous elements: sociology, ethics, psychology, political science. 3. KEY CONCEPTS: 4. (i) LAW as a system of NORMS — 'OUGHT' statements (not facts); 5. (ii) HIERARCHICAL STRUCTURE (Stufenbau) — each norm derives validity from a higher norm; 6. (iii) GRUNDNORM (basic norm, hypothetical) — the ultimate normative presupposition that gives validity to the constitution; 7. (iv) Distinguishes 'IS' (sein) from 'OUGHT' (sollen) — law is the realm of 'ought'; 8. (v) Coercion as a defining feature of law. 9. CRITICISMS: H.L.A. Hart criticised the Grundnorm as fictitious; sociological school criticised purity as unrealistic. 10. Hence option B is correct. _Source: Legal Research Methodology + Jurisprudence — Hans Kelsen, 'Pure Theory of Law' (1934/1960)_