Select the socio-economic framework that most accurately describes the doctrine of 'socialism' as implemented within the Indian Constitution:
1. A system requiring the aggressive nationalization of all fundamental, key industrial sectors.
2. A framework enforcing the total eradication of private capital and complete state ownership of all material resources.
3. A rigid application of 'state socialism' wherein the government operates as an absolute economic monopoly.
4. A hybrid model ensuring personal economic liberty while maintaining centralized social control to promote welfare.