Assertion: An optimum location for iron and steel industries should be near raw material sources.
Reasoning: In iron and steel industries, iron ore and coal both are weight-losing raw materials.

Both Assertion (A) and reasoning (R) are correct and R is the correct explanation of A.

Industries using weight-losing raw materials are located in the regions where raw materials are located. In iron and steel industries, iron ore and coal both are weight-losing raw materials. Therefore, an optimum location for iron and steel industries should be near raw material sources. This is why most of the iron and steel industries are located either near coalfields (Bokaro, Durgapur, etc.) or near sources of iron ore (Bhadravati, Bhilai, and Rourkela). Similarly, industries based on perishable raw materials are also located close to raw material sources.