The correct answer is (d) Hyderabad.
A megacity is a city with a population of over 10 million people. As per the 2001 Census, the population of Hyderabad was 7.7 million. The other three cities, Ahmedabad, Chennai, and Bangalore, had populations of 5.1 million, 4.6 million, and 5.7 million, respectively.
Hyderabad is the capital of the Indian state of Telangana. It is located in the Deccan Plateau and is the sixth most populous city in India. The city is known for its historical monuments, including the Charminar and Golconda Fort. It is also a major center for education, technology, and healthcare.
Ahmedabad is the largest city in the Indian state of Gujarat. It is located on the banks of the Sabarmati River and is the seventh most populous city in India. The city is known for its textile industry and is also a major center for education, culture, and tourism.
Chennai is the capital of the Indian state of Tamil Nadu. It is located on the Coromandel Coast and is the fourth most populous city in India. The city is known for its film industry, known as Kollywood, and is also a major center for education, technology, and healthcare.
Bangalore is the capital of the Indian state of Karnataka. It is located in the Deccan Plateau and is the fifth most populous city in India. The city is known for its IT industry and is also a major center for education, culture, and tourism.