Greatest producers of organic matter are

Options

A. Crop plants
B. Forests
C. Plants of the land area
D. Phytoplankton of oceans.

Answer

**Step-by-Step Solution:**

1. **Understanding Organic Matter Production**: Organic matter is produced through the process of photosynthesis, where plants convert carbon dioxide and sunlight into glucose and oxygen.

2. **Identifying the Options**: The options provided are:
- A) Green plants
- B) Forests
- C) Plants on land area
- D) Phytoplankton of the ocean

3. **Evaluating Each Option**:
- **Green Plants**: They are significant producers of organic matter, but they primarily exist on land.
- **Forests**: Forests consist of many green plants and are important for organic matter production, but they are still limited to terrestrial environments.
- **Plants on Land Area**: This includes all terrestrial plants, which contribute to organic matter but are not the greatest producers.
- **Phytoplankton of the Ocean**: These are microscopic plants that live in the ocean and are known to be the largest producers of organic matter.

4. **Analyzing Phytoplankton's Contribution**: Phytoplankton are responsible for fixing a significant amount of carbon dioxide, estimated to be around 90% of the total carbon dioxide fixed by all plants. They produce organic matter on a much larger scale compared to terrestrial plants.

5. **Conclusion**: Based on the analysis, the greatest producers of organic matter are the phytoplankton of the ocean.

**Final Answer**: The greatest producers of organic matter are the phytoplankton of the ocean.

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