The correct answer is option 2: Manganese and limestone.

When smelting iron ore, two minerals are essential: manganese and limestone. Manganese is used as an alloying agent in the production of iron and helps improve its strength and flexibility. Limestone, on the other hand, is used as a fluxing agent. It helps remove impurities from the iron ore during the smelting process by reacting with them and forming slag. The slag, which is made up of the impurities, floats on top of the molten iron and can be easily removed.

Option 1, limestone, and gypsum are not required for smelting iron ore. Gypsum is commonly used in construction materials, while limestone is mainly used in cement production.

Option 3, limestone, and coal are not the correct minerals for smelting iron ore. Coal is used as a source of carbon to reduce iron oxide to iron during the smelting process, but limestone is needed for its fluxing properties.

Option 4, gypsum, and coal are also not the required minerals for smelting iron ore. Gypsum is not involved in the smelting process, and coal is only used as a source of carbon.

In summary, the correct minerals