Largest ecosystems in the world are:

Options

A. Forests
B. Grasslands
C. Great lakes
D. Oceans

Answer

**Step-by-Step Solution:**

1. **Identify the Question**: The question asks about the largest ecosystems in the world from the given options: forests, grasslands, great lakes, and oceans.

2. **Analyze Each Option**:
- **Forests**: Forests cover approximately 31% of the Earth's land area, which is significant but not the largest ecosystem.
- **Grasslands**: Grasslands cover between 20% to 40% of the Earth's surface, but this is still less than the coverage of oceans.
- **Great Lakes**: The Great Lakes cover about 21% of the world's freshwater surface, which is also not extensive enough to be considered the largest ecosystem.
- **Oceans**: Oceans cover about 78% of the Earth's surface, making them the largest ecosystem by a significant margin.

3. **Conclusion**: Based on the analysis, the correct answer is oceans, as they occupy the largest area compared to the other ecosystems listed.

4. **Final Answer**: The largest ecosystems in the world are oceans.

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