Explanation:

Correct option 3: Duguit

The statement “He pushed natural law out through the door and let it come back through the window” was made about Léon Duguit, a French jurist and a key figure in the Sociological School of Law.

• Duguit rejected traditional natural law doctrines based on metaphysical or divine origin.

• However, he introduced the idea of an objective social solidarity as the basis for law, which many critics argued was natural law in disguise, as it appealed to an inherent, universal principle of social behavior.

• Hence, the criticism was that Duguit tried to eliminate natural law but ended up reintroducing it under a different name — leading to the famous remark.