Industrial melanism is related to-

Options

A. Skin darkening due to smoke
B. Drug resistance
C. Defence against UV radiations
D. Protective resemblance to surroundings

Answer

**Step-by-Step Solution:**

1. **Understanding Industrial Melanism**: Industrial melanism refers to the phenomenon where darker-colored individuals of a species become more common in industrial areas due to pollution. This is primarily observed in species like the peppered moth (Biston betularia).

2. **Identifying the Options**: The question provides four options related to industrial melanism:
- Option 1: Skin darkening due to smoke
- Option 2: Drug resistance
- Option 3: Defense against UV radiation
- Option 4: Protective resemblance to surroundings

3. **Evaluating Each Option**:
- **Option 1**: Skin darkening due to smoke is incorrect because it does not relate to the concept of industrial melanism, which is about species adaptation, not human skin changes.
- **Option 2**: Drug resistance is also incorrect as it pertains to the ability of organisms to survive exposure to drugs, which is unrelated to the concept of industrial melanism.
- **Option 3**: Defense against UV radiation does not apply here, as industrial melanism is not about UV protection but rather about color adaptation in response to environmental changes.
- **Option 4**: Protective resemblance to surroundings is correct. This option aligns with the concept of industrial melanism, where the darker coloration of the moths allowed them to blend into soot-darkened environments, thus providing better camouflage against predators.

4. **Conclusion**: Based on the evaluations, the correct answer is **Option 4: Protective resemblance to surroundings**. This highlights how species adapt their coloration to better survive in changing environments, a key principle of natural selection.

---