Melanin present in the skin is useful in

Options

A. Prevention of overheating
B. Reflecting solar radiations
C. Protection form ultra-violet radiations
D. All the above.

Answer

**Step-by-Step Solution:**

1. **Understanding Melanin**: Melanin is a pigment found in the skin, responsible for the color of our skin, hair, and eyes. It is produced by cells called melanocytes.

2. **Types of Melanin**: There are two primary types of melanin: eumelanin (which is dark brown or black) and pheomelanin (which is yellow or red). The type and amount of melanin determine the pigmentation of the skin.

3. **Function of Melanin**: One of the key functions of melanin is to protect the skin from ultraviolet (UV) radiation. UV radiation from the sun can cause damage to the skin, leading to sunburn and increasing the risk of skin cancer.

4. **Mechanism of Protection**: Melanin absorbs and disperses UV radiation, preventing it from penetrating deeper into the skin layers. This filtering effect helps to reduce the harmful effects of UV rays.

5. **Other Functions**: While melanin does play a role in preventing overheating and reflecting some solar radiation, its primary and most significant function is the protection against UV radiation.

6. **Conclusion**: Given the options provided, the most accurate answer is that melanin is primarily useful for protection from ultraviolet radiations.

**Final Answer**: Protection from the ultraviolet radiations.

---