The correct answer is option 4: Six years. Members of the Rajya Sabha, which is the upper house of the Parliament of India, are elected for a term of six years. This differs from the Lok Sabha, which is the lower house, where members are elected for a term of five years. The Rajya Sabha provides continuity in the legislative process as only one-third of its members retire every two years, ensuring that the house remains stable. The members of the Rajya Sabha are elected by the members of the State Legislative Assemblies, using the system of proportional representation by means of the single transferable vote.