Assertion : The clouds in the sky generally appear to be whitish.
Reason : Diffraction due to clouds is efficient in equal measures its all wavelengths.

Options

A. If both assertion and reason are true and reason is the correct explanation of assertion
B. If both assertion and reason are true but reason is not the correct explanation of assertion
C. If assertion is true but reason is false
D. If both assertion and reason are false

Explanation

To solve the given question, we will analyze both the assertion and the reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion:**
- The assertion states that "The clouds in the sky generally appear to be whitish."
- This is a true statement. Clouds often appear white due to the scattering of sunlight by the water droplets and ice crystals present in them.

2. **Understanding the Reason:**
- The reason given is "Diffraction due to clouds is efficient in equal measures for all wavelengths."
- This statement is misleading. While diffraction can occur, it is not the primary reason for the whitish appearance of clouds. The size of the water droplets in clouds is typically much larger than the wavelength of visible light, which leads to minimal diffraction.

3. **Analyzing the Scattering Phenomenon:**
- The primary phenomenon responsible for the whitish appearance of clouds is Rayleigh scattering, which occurs when light interacts with particles that are comparable in size to the wavelength of light.
- In clouds, the particles (water droplets) are large compared to the wavelength of visible light, leading to minimal scattering of individual colors. Instead, all colors of light are scattered equally, resulting in the perception of white light.

4. **Conclusion:**
- The assertion is true because clouds do appear whitish.
- The reason provided is false because diffraction is not the main cause of the whitish appearance of clouds; rather, it is due to the scattering of light.

5. **Final Answer:**
- Assertion is true, but the reason is false. Therefore, the correct option is that the assertion is true and the reason is false.