The correct answer is option 4: None of the above. The Rajya Sabha, one of the two houses of the Indian Parliament, is not dissolved after a specific time period like the Lok Sabha. Members of the Rajya Sabha serve for a term of six years. However, unlike the Lok Sabha, the Rajya Sabha is a continuing chamber, meaning that it is not subjected to dissolution at the same time as the Lok Sabha. The Rajya Sabha is a permanent body and only one-third of its members retire every two years. Therefore, option 1 (every five years) and option 2 (every six years) are incorrect. Option 3 (on the advice of the Prime Minister) is also incorrect as the Prime Minister does not have the power to dissolve the Rajya Sabha.