Which of the following is an ore?

Options

A. Haematite
B. Bauxite
C. Magnetite
D. All of these

Answer

To determine which of the following is an ore, we need to analyze the options provided: hematite, bauxite, magnetite, or all of these.

### Step-by-Step Solution:

1. **Understand the Definition of an Ore**:
An ore is a naturally occurring solid material from which a metal or valuable mineral can be extracted profitably.

2. **Analyze Each Option**:
- **Hematite**: This is an iron oxide (Fe₂O₃) and is one of the main ores of iron. It is commonly used in the extraction of iron.
- **Bauxite**: This is the primary ore of aluminum. It consists mainly of aluminum oxide minerals and is used to extract aluminum.
- **Magnetite**: This is another iron oxide (Fe₃O₄) and is also an important ore of iron. It is magnetic and has a higher iron content compared to hematite.

3. **Conclusion**:
Since all three options (hematite, bauxite, and magnetite) are ores from which metals can be extracted, we conclude that all of these are ores.

4. **Final Answer**:
Therefore, the correct answer is "all of these".