Coating iron and steel article with chromium metal is done through:

Options

A. greasing
B. galvanisation
C. electroplating
D. All of these

Explanation

To answer the question, "Coating iron and steel articles with chromium metal is done through:", we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Need for Coating**:
- Iron and steel are prone to corrosion when exposed to air and moisture. This corrosion can lead to degradation of their properties, strength, and appearance.

**Hint**: Think about why metals need protection from the environment.

2. **Identifying the Coating Material**:
- Chromium is chosen for coating because it provides a protective layer that prevents oxidation and corrosion of the underlying metal.

**Hint**: Consider the properties of chromium that make it suitable for protecting other metals.

3. **Defining the Coating Process**:
- The process of applying a layer of one metal onto another is known as electroplating. This involves using an electric current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode.

**Hint**: Recall the term used when one metal is deposited onto another using electricity.

4. **Specific Type of Electroplating**:
- When chromium is specifically used for this electroplating process, it is referred to as chrome plating.

**Hint**: Think about the specific name given to the process when chromium is used in electroplating.

5. **Conclusion**:
- Therefore, the correct answer to the question is that coating iron and steel articles with chromium metal is done through electroplating, specifically chrome plating.

### Final Answer:
Coating iron and steel articles with chromium metal is done through **electroplating** (specifically **chrome plating**).