The correct option is B Uttar Pradesh
Census in India is conducted every ten years. The 15th Indian census of 2011, was conducted in two phases. The population percentages of states with respect to the total population were measured as Andhra Pradesh 6.99%, Uttar Pradesh 16.5%, Madhya Pradesh 6% and Karnataka 5.05%. Uttar Pradesh was the most populated state in India. Hence, option B is the correct answer.