Which of the following is a non-luminous object?

Options

A. Sun
B. Stars
C. Earth
D. Firefly

Answer

To determine which of the following is a non-luminous object, we need to understand the definitions of luminous and non-luminous objects.

### Step-by-Step Solution:

1. **Define Luminous Objects**:
- Luminous objects are those that can produce their own light. They emit light due to various processes, such as nuclear fusion or biochemical reactions.

2. **Examples of Luminous Objects**:
- The Sun: It produces light through nuclear fusion, where hydrogen atoms combine to form helium, releasing energy in the form of light.
- Stars: Similar to the Sun, stars also produce their own light through nuclear fusion.
- Firefly: This is a living organism that produces light through biochemical processes in its body.

3. **Define Non-Luminous Objects**:
- Non-luminous objects do not produce their own light. Instead, they reflect light from luminous objects.

4. **Examples of Non-Luminous Objects**:
- Earth: The Earth does not produce its own light; it reflects light from the Sun. Therefore, it is classified as a non-luminous object.

5. **Conclusion**:
- Among the options provided, the non-luminous object is Earth.

### Final Answer:
The non-luminous object is Earth.

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