The correct option is C 1989
The Indian constitution adopts Universal adult franchise as a basis of elections to the Lok Sabha and State legislative assemblies. Every citizen who is or above 18 years of age has a right to vote without any discrimination of caste, race , religion, sex, literacy, etc. The voting age was reduced from 21 to 18 by the Parliament in the year 1989 by the 61st Constitutional Amendment Act of 1988.