The correct option is D All of these
Organization of the elections was a wondrous task. There was a house-to-house survey to register the voters. With over 70 per cent of the voters being illiterate, the candidates were to be identified by symbols, assigned to each major party and independent candidates, painted on the ballot-boxes (this was later changed to symbols on the ballot papers). The voters were to place the ballot papers in the box assigned to a particular candidate, and ballot was secret. Over 224,000 polling booths, one for almost every 1000 voters, were constructed and equipped with over 21/2 million steel ballot-boxes, one box for every candidate.