The representatives to the Constituent Assembly in India were chosen by the Provincial Legislatures. The members of the Constituent Assembly were elected by the members of the various Provincial Legislative Assemblies based on a system of proportional representation by means of the single transferable vote. Each province and princely state were allocated a certain number of seats in the Constituent Assembly based on their population. This process allowed for the representation of diverse regions and communities in the assembly, contributing to the framing of the Indian Constitution with a broad and inclusive perspective.

So, the correct option is [3].