The correct answer is (b) Gautam Budh Nagar.
Gautam Budh Nagar is a district in the Indian state of Uttar Pradesh. It is the smallest district in Uttar Pradesh, with a total area of 1,295 square kilometers. The district is located in the northern part of the state, and is bordered by the districts of Meerut, Bulandshahr, Aligarh, and Ghaziabad. The district is named after Gautama Buddha, who was born in Lumbini, Nepal, which is now part of Gautam Budh Nagar district.
The district is home to a number of important historical and religious sites, including the Sarnath Buddhist complex, the Dashratha Temple, and the Atal Tunnel. The district is also home to a number of important industrial and commercial centers, including the Noida and Greater Noida industrial areas.
The district has a population of over 3 million people, and is the most populous district in Uttar Pradesh. The district is home to a number of different ethnic groups, including the Brahmins, the Rajputs, the Jats, and the Muslims. The district is also home to a number of different languages, including Hindi, Urdu, and Punjabi.
The district is governed by a district magistrate, who is appointed by the state government. The district is also divided into a number of tehsils and blocks. The tehsils are further divided into a number of villages.
The district is a major tourist destination, and is home to a number of important historical and religious sites. The district is also home to a number of important industrial and commercial centers.