Answer:
Poland is one of the major producers of copper and silver in the world. It is also a significant producer of coal, zinc, lead, and other industrial minerals. The mining industry is an important part of the Polish economy, with mining and quarrying accounting for around 3% of the GDP and providing jobs for over 100,000 people. Poland's natural resources have contributed significantly to its economic development and continue to play a significant role in its growth.
Therefore, the answer is 1. Iron Ore.