Which of the following processes of decomposition produces a substance resistant to microbial action?

Options

A. catabolism
B. mineralisation
C. humification
D. leaching

Answer

To solve the question "Which of the following processes of decomposition produces a substance resistant to microbial action?" we need to analyze the given options: Catabolism, Mineralization, Humification, and Leaching.

### Step-by-Step Solution:

1. **Understanding Decomposition**:
- Decomposition is the process where complex organic matter is broken down into simpler inorganic substances. This includes the breakdown of dead plant and animal matter.

2. **Identifying the Processes**:
- **Catabolism**: This involves the breakdown of organic matter by bacterial and fungal enzymes into simple inorganic substances. While it does break down materials, it does not specifically produce substances resistant to microbial action.

- **Mineralization**: This is the process that occurs after decomposition, where nutrients are released from organic matter. It does not produce a resistant substance but rather makes nutrients available for plants.

- **Leaching**: This process involves the washing away of soluble nutrients from the soil. It results in the loss of nutrients rather than the creation of resistant substances.

- **Humification**: This process involves the breakdown of organic matter into a dark-colored, amorphous substance known as humus. Humus is highly resistant to microbial action and decomposes at a slow rate.

3. **Conclusion**:
- Among the options provided, **Humification** is the process that produces a substance (humus) that is resistant to microbial action.

### Final Answer:
- The correct answer is **Humification**.