Identify the primary structural rationale that leads political scholars to classify the Indian state as a 'quasi-federal' polity:
1. The national executive is bound by the doctrine of collective responsibility to the central legislative assembly.
2. The architectural design incorporates a bicameral legislature at both the national and provincial tiers.
3. The governance model distributes authority between regional and national levels, but deliberately skews supreme power toward the central government.
4. The framework strictly adheres to an absolute, mathematical division of equal power between the Union and the States.