The correct answer is: d) All of the above.
Tamil Nadu is a leading producer of limestone, magnesite, and graphite.
Limestone is a sedimentary rock composed of calcium carbonate. It is used in a variety of industries, including construction, cement, and iron and steel. Tamil Nadu is the second largest producer of limestone in India, after Rajasthan.
Magnesite is a magnesium carbonate mineral. It is used in a variety of industries, including refractory, chemical, and metallurgical. Tamil Nadu is the largest producer of magnesite in India.
Graphite is a form of carbon. It is used in a variety of industries, including batteries, lubricants, and refractories. Tamil Nadu is the second largest producer of graphite in India, after Andhra Pradesh.