The Donimalai region of Karnataka is known for its reserves of:

Iron ore
Copper
Limestone
Manganese

The correct answer is: A) Iron ore.

The Donimalai region of Karnataka is known for its reserves of iron ore. The region is home to several iron ore mines, including the Donimalai Iron Ore Mine, which is one of the largest iron ore mines in India. The iron ore from the Donimalai region is high quality and is used in the manufacture of steel.

The other options are incorrect. Copper is found in the Khetri Copper Belt in Rajasthan. Limestone is found in the Bhima Basin in Karnataka. Manganese is found in the Chitradurga district of Karnataka.

Iron ore is a mineral that is used to make steel. It is the most common metal in the Earth’s crust and is found in rocks and minerals all over the world. Iron ore is mined and then processed to remove impurities. The resulting iron is then used to make steel. Steel is a strong and durable material that is used in a variety of products, including buildings, cars, and appliances.

The Donimalai region of Karnataka is located in the southern part of the state. The region is known for its iron ore reserves and is home to several iron ore mines. The iron ore from the Donimalai region is high quality and is used in the manufacture of steel.