Correct option is D
The "Critical school" is not traditionally recognized as one of the main schools of jurisprudence. The major classical schools include the Historical School (e.g., Savigny), Realist School (e.g., Holmes, Llewellyn), Sociological School (e.g., Duguit, Ehrlich), and Analytical School (e.g., Austin, Bentham). Although Critical Legal Studies (CLS) is a modern movement in legal thought (emerging in the 1970s in the USA), it is not categorized as one of the classical traditional "schools" of jurisprudence. Thus, "Critical School" is not part of traditional jurisprudential classification.
Information Booster:
Historical School: Law evolves with the spirit of the people (Volksgeist). (Key thinker: Savigny)
Realist School: Law is what courts actually do, not just what is written in statutes. (Key thinkers: Holmes, Llewellyn)
Sociological School: Law serves social purposes and adapts to social needs. (Key thinkers: Roscoe Pound, Duguit)
Analytical School: Focuses on law as it is (positive law) without considering its moral or social aspects. (Key thinkers: Austin, Bentham)