Possible early source of energy was

Options

A. Chlorophyll
B. `CO_(2)`
C. UV radiation and lightning
D. Green plants

Answer

**Step-by-Step Solution:**

1. **Understanding the Question:** The question asks for the possible early source of energy on primitive Earth.

2. **Analyzing the Options:**
- **Chlorophyll:** This is a pigment found in plants that is essential for photosynthesis. However, during the early stages of Earth's history, there were no plants or chlorophyll present.
- **Carbon Dioxide:** While carbon dioxide is a component of the atmosphere, it was not a direct source of energy. Additionally, the early atmosphere was likely rich in nitrogen, methane, and ammonia rather than carbon dioxide.
- **UV Radiation and Lightning:** These are forms of energy that could have been present on early Earth. UV radiation comes from the Sun, and lightning is a result of electrical discharges in the atmosphere.
- **Green Plants:** Similar to chlorophyll, green plants did not exist in the early Earth environment, as photosynthetic organisms had not yet evolved.

3. **Identifying the Correct Answer:** Given the analysis, the most plausible early source of energy is UV radiation and lightning. These sources would have provided the energy necessary for the chemical reactions that led to the formation of organic compounds.

4. **Conclusion:** Therefore, the correct answer is **UV radiation and lightning**.

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