The correct option is (b).
Explanation
In optics, objects are classified based on their ability to emit light. Luminous objects are sources that generate and emit their own light. Illuminated (or non-luminous) objects do not emit light themselves; they become visible only when light from a luminous source falls on them and is reflected to the observer's eyes.
Statement-wise Analysis:
- Statement 1 is Incorrect. The Sun and a candle flame generate their own light through nuclear fusion and chemical combustion, respectively. Therefore, they are classified as luminous objects, not illuminated objects.
- Statement 2 is Correct. The Moon does not produce its own light. It shines because it reflects the sunlight falling on its surface. Consequently, it is an example of an illuminated object.
- Statement 3 is Incorrect. By definition, illuminated objects do not emit their own light. They only reflect light originating from other sources. It is luminous objects that emit their own light.
Key Takeaway:
The primary distinction in optics regarding visibility is that luminous objects are light sources (e.g., Sun, stars, bulbs), while illuminated objects are visible solely due to the reflection of light (e.g., Moon, planets, wood).