What is the minimum age to be an eligible voter for Lok Sabha elections?

18 years

The correct answer is Option 3 - 18 years

In India, the minimum age requirement to be an eligible voter for Lok Sabha elections, as well as for elections to State Legislative Assemblies, is 18 years. This provision is enshrined in the Representation of the People Act, 1950, which governs the conduct of elections in India.