The correct option is C 1988
The voting age of elections to the Lok Sabha and to the Legislative Assemblies of States was lowered from 21 years to 18 years through the Sixty-first Amendment of the Constitution of India, officially known as The Constitution (Sixty-first Amendment) Act, 1988. Article 326 of the Constitution, which concerns to elections to the Lok Sabha and the Assemblies, was amended to effect this change.