Which two minerals are commercial sources of iron. explain why the answer is a?

Hematite and magnetite

Explanation:

Minerals such as Iron don't occur alone due to its interaction with other elements. The Iron's major source is usually through ores such as Hematite, Magnetite, limonite etc.

However Pure magnetite contains 72.4 percent iron and pure hematite contains 69.9 percent. They have the highest percentage of iron thereby making them the main sources.