H.L.A. HART's 'THE CONCEPT OF LAW' (1961) advanced a sophisticated POSITIVIST theory distinguishing:

1. H.L.A. Hart (1907-1992), Professor of Jurisprudence at Oxford, transformed analytical jurisprudence with his 'The Concept of Law' (1961). 2. Key concept: UNION of PRIMARY and SECONDARY rules: 3. (i) PRIMARY RULES — rules of conduct imposing obligations (substantive law); 4. (ii) SECONDARY RULES — rules about primary rules: 5. (a) RULE OF RECOGNITION — identifies what counts as law in the system (analogous to Kelsen's Grundnorm but socially constituted, not hypothetical); 6. (b) RULES OF CHANGE — how laws are made and amended; 7. (c) RULES OF ADJUDICATION — how disputes are resolved. 8. Hart criticised Kelsen and Austin: law cannot be reduced to commands or norms alone. 9. Hart vs Dworkin debate (Ronald Dworkin's 'Law's Empire' 1986) is foundational to modern jurisprudence. 10. Hence option B is correct. _Source: Legal Research Methodology + Jurisprudence — H.L.A. Hart, 'The Concept of Law' (1961, second edition 1994)_