Organic manure formed by Earthworm is

Options

A. Worm casting
B. Urea
C. Ammonia
D. Vermiculture

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the type of organic manure formed by earthworms.

2. **Identifying Key Terms**: The key terms in the question are "organic manure" and "earthworm".

3. **Exploring Earthworm Functions**: Earthworms play a significant role in soil health. They consume organic waste and soil, which they digest.

4. **Formation of Organic Manure**: As earthworms digest organic matter, they produce a nutrient-rich substance known as humus. This humus is what qualifies as organic manure.

5. **Terminology**: The excreta of earthworms, which is rich in nutrients and beneficial for soil health, is referred to as "worm casting".

6. **Conclusion**: Based on the above points, the organic manure formed by earthworms is known as "worm casting".

7. **Final Answer**: The correct answer to the question is **worm casting**.