The correct answer is (a). Uttar Pradesh, Maharashtra, and Bihar.
Uttar Pradesh is the most populous state in India, with a population of over 200 million people. Maharashtra is the second most populous state, with a population of over 110 million people. Bihar is the third most populous state, with a population of over 100 million people. Together, these three states account for over 300 million people, which is more than one-third of India’s population.
The other options are incorrect. Option (b) is incorrect because Andhra Pradesh is not one of the most populous states in India. Option (c) is incorrect because Tamil Nadu and West Bengal are not among the top three most populous states in India. Option (d) is incorrect because Madhya Pradesh is not among the top three most populous states in India.