The correct answer is option 2, thirty years. To become a member of Rajya Sabha, one must be at least thirty years old. Option 1, twenty years, is incorrect as it does not meet the minimum age requirement. Option 3, twenty-two years, is also incorrect as it is below the required age. Option 4, twenty-five years, is also incorrect as it still falls short of the minimum age requirement. Therefore, option 2 is the correct answer as it accurately states the minimum age required to become a member of Rajya Sabha.