The correct answer is option 1, Japan. India exports iron ore mainly to Japan. Iron ore is a mineral resource that is widely used in various industries, including steel production. Japan is one of the largest importers of iron ore in the world, and India is a significant exporter of this mineral. Japan`s strong industrial base and high demand for iron ore make it an important market for India`s iron ore exports. While options 2, 3, and 4 (Bhutan, Indonesia, and Russia) may also be involved in iron ore trade, they are not the main destinations for India`s iron ore exports.