The correct answer is The Government of India Act, 1935, as the structural part of the Indian Constitution has been largely derived from this Act.
Background:
The Government of India Act, 1935 was the most comprehensive legislation enacted by the British Parliament to govern British India. It laid down a detailed administrative framework for the governance of the country and introduced significant structural reforms.
Key Structural Features Adopted from the 1935 Act:
1. Federal Structure: Although not fully implemented under British rule, the federal system provided in the Act influenced the federal features of the Indian Constitution.
2. Division of Powers: The three-fold division of legislative subjects into the Union List, Provincial List (now State List), and Concurrent List was borrowed from the 1935 Act.
3. Office of the Governor: The powers and responsibilities of the Governor at the state level were drawn from the 1935 Act.
4. Emergency Provisions: Several emergency-related powers of the center were modeled on provisions in the 1935 Act.
5. Bicameral Legislature: The concept of having two Houses at the center (Lok Sabha and Rajya Sabha) was influenced by the federal legislature structure in the 1935 Act.
6. Public Service Commissions: The establishment of the Union and State Public Service Commissions was also derived from this Act.
Conclusion:
The structural framework—including administrative divisions, governance principles, and institutional mechanisms—of the Indian Constitution owes much to The Government of India Act, 1935, making it a crucial historical foundation for the modern Indian state.