Which of the following made Ralegan Siddhi independent of government’s financial aid?

Class 12th Geography, Question -Which of the following made Ralegan Siddhi independent of government's financial aid?

These are the options for the question :Which of the following made Ralegan Siddhi independent of government’s financial aid?

(a) Prohibition of liquor
(b) Voluntary labour
(c) Local body election
(d) Agriculture

The correct answer is -(b) Voluntary labour