The sun is seen before the actual sun rise because of _______

Options

A. reflection
B. refraction
C. scattering of light
D. rectilinear propagation of light

Answer

To answer the question, "The sun is seen before the actual sunrise because of _______", we need to understand the phenomenon that allows us to see the sun before it has actually risen above the horizon.

### Step-by-Step Solution:

1. **Understanding Refraction**: The key concept here is refraction, which is the bending of light as it passes from one medium to another. In this case, light from the sun travels through the Earth's atmosphere, which consists of layers of air with varying densities.

2. **Atmospheric Layers**: The Earth's atmosphere is denser closer to the surface and becomes less dense as you go higher. When the light rays from the sun enter the atmosphere, they move from a rarer medium (space) to a denser medium (the atmosphere).

3. **Bending of Light**: As the light rays travel from the rarer medium to the denser medium, they bend towards the normal line (an imaginary line perpendicular to the surface at the point of incidence). This bending causes the apparent position of the sun to be higher in the sky than its actual position.

4. **Seeing the Sun Before Sunrise**: Because of this bending of light, we can see the sun slightly before it actually crosses the horizon. The light rays reach our eyes from the sun's actual position, which is below the horizon, but due to refraction, they appear to come from a position above the horizon.

5. **Conclusion**: Therefore, the correct answer to the question is that the sun is seen before the actual sunrise because of **refraction** of light in the Earth's atmosphere.

### Final Answer:
The sun is seen before the actual sunrise because of **refraction**.

---