The correct answer is A. Gurugram.
Gurugram, formerly known as Gurgaon, is a city in the northern Indian state of Haryana. It is situated in the National Capital Region and is one of the most populous cities in India. Gurugram is a major financial and technology hub and is home to many multinational companies. The city has a population of over 10 million people, making it the most populous district in Haryana.
Panipat is a city in the Indian state of Haryana. It is located on the banks of the Yamuna River, about 90 kilometers north of Delhi. Panipat is a major industrial and commercial center and is home to many textile mills, engineering industries, and chemical plants. The city has a population of over 1.5 million people.
Hisar is a city in the Indian state of Haryana. It is located in the northern part of the state, about 150 kilometers from Delhi. Hisar is a major agricultural and educational center and is home to many universities and colleges. The city has a population of over 1 million people.
Faridabad is a city in the Indian state of Haryana. It is located in the southern part of the state, about 30 kilometers from Delhi. Faridabad is a major industrial and commercial center and is home to many automobile and electronics companies. The city has a population of over 2 million people.
In conclusion, the correct answer is A. Gurugram. Gurugram is the most populous district in Haryana and is a major financial and technology hub.