Humus is

Options

A. Dead and decayed organic matter
B. Living matter
C. Fertilizers
D. Living animal/plants/microbes

Answer

**Step-by-Step Solution:**

1. **Understanding Humus**: Humus is a dark organic material found in soil. It is formed from the decomposition of plant and animal matter.

2. **Source of Humus**: The primary sources of humus are dead and decayed organic matter, which includes fallen leaves, twigs, and the remains of dead animals.

3. **Process of Formation**: When plants shed leaves and when animals die, their remains accumulate on the ground. This accumulation is referred to as leaf litter.

4. **Decomposition**: Over time, the leaf litter and animal remains undergo decomposition. Microorganisms, fungi, and other decomposers break down this organic matter.

5. **Transformation into Humus**: As the decomposition process continues, the organic matter transforms into humus, which enriches the soil with nutrients.

6. **Conclusion**: Based on the above points, humus can be defined as dead and decayed organic matter. Thus, the correct answer to the question is the first option: "dead and decayed organic matter."

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