The correct answer is option 3, 1956. In 1956, the Indian states were reorganized on the basis of linguistic differences. This means that states were divided or merged based on the predominant language spoken in that region. The reorganization was done to address the demands for linguistic states and to promote cultural and linguistic diversity in the country. This move was significant as it helped in the administration of states and facilitated better governance. The linguistic reorganization of states played a crucial role in preserving and promoting different languages, cultures, and identities in India.