The correct answer is Salem.
Salem is a district in the Indian state of Tamil Nadu. It is located in the northern part of the state and is bordered by the districts of Namakkal, Erode, Coimbatore, Dharmapuri, and Krishnagiri. The district has a population of over 3.5 million people and is the third most populous district in Tamil Nadu.
Salem is known for its production of traditional ‘Salem’ steel. Salem steel is a type of steel that is made from iron ore that is found in the district. The steel is known for its high quality and is used in a variety of industries, including the construction industry, the automobile industry, and the engineering industry.
The other options are incorrect because they are not districts in Tamil Nadu. Erode is a district in the southern part of the state, Namakkal is a district in the western part of the state, and Dharmapuri is a district in the eastern part of the state.