Which of the following maintains the organic matter of the soil?

Options

A. Fungi and semiparasites
B. Cyanobacteria and parasitic animals
C. Bacteria and fungi
D. All of these

Explanation

To answer the question "Which of the following maintains the organic matter of the soil?", we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Organisms**: The options given include fungi and semi-parasites, cyanobacteria and parasitic animals, bacteria and fungi, and all of these. We need to determine which of these organisms is primarily responsible for maintaining organic matter in the soil.

2. **Understand the Role of Decomposers**: Decomposers, which include bacteria and fungi, play a crucial role in the ecosystem. They break down dead organic matter, such as dead plants and animals, into simpler substances.

3. **Process of Decomposition**: During decomposition, complex organic materials are converted into simpler substances like nutrients, carbon dioxide, and water. This process enriches the soil with nutrients that are essential for plant growth.

4. **Nutrient Recycling**: The nutrients released during decomposition are absorbed by plants, which need them for growth and development. Thus, bacteria and fungi are vital for recycling nutrients back into the soil.

5. **Conclusion**: Among the options provided, bacteria and fungi are the primary organisms that maintain the organic matter of the soil through their role as decomposers. Therefore, the correct answer is **bacteria and fungi**.

### Final Answer:
The correct option is **3rd, Bacteria and Fungi**.

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