The process of converting vapor into liquid is known as

Options

A. condensation
B. vaporisation
C. freezing
D. melting

Explanation

To solve the question "The process of converting vapor into liquid is known as," we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Terms**:
- We need to identify the process that specifically refers to the change from vapor (gas) to liquid.

2. **Identifying the Correct Process**:
- The process of converting vapor into liquid is known as **condensation**. This occurs when the temperature of the vapor decreases or when the pressure increases, leading to the formation of liquid droplets.

3. **Differentiating from Other Processes**:
- To ensure clarity, let's differentiate condensation from other related processes:
- **Vaporization**: This is the process where a liquid turns into vapor (gas).
- **Freezing**: This is the process where a liquid turns into a solid.
- **Melting**: This is the process where a solid turns into a liquid.

4. **Conclusion**:
- Therefore, the correct answer to the question is **condensation**.

### Final Answer:
The process of converting vapor into liquid is known as **condensation**.