Find the odd one out:

Options

A. vaccines - immunology
B. eco degradation - pesticides
C. solar energy converter - pest control
D. recombinant DNA - biotechnology

Answer

To solve the question "Find the odd one out," we will analyze each option provided and determine which one does not fit with the others based on their associations.

### Step-by-Step Solution:

1. **Analyze Option 1: Vaccines**
- Vaccines are antigenic preparations that stimulate the immune system to produce memory cells. This process is directly related to immunology.
- **Conclusion:** This option is correctly associated with immunology.

2. **Analyze Option 2: Ecodegradation**
- Ecodegradation refers to the degradation of the environment, often due to the injudicious use of pesticides. This impacts the ecosystem and disrupts food chains.
- **Conclusion:** This option is correctly associated with environmental science.

3. **Analyze Option 3: Solar Energy Converter**
- A solar energy converter is a device that transforms solar energy into usable energy. Pest control does not relate to energy conversion.
- **Conclusion:** This option is incorrectly matched as it does not relate to the concept of energy conversion.

4. **Analyze Option 4: Recombinant DNA (Biotechnology)**
- Recombinant DNA technology (RDT) is a biotechnological method used to manipulate DNA for various applications, including genetic engineering.
- **Conclusion:** This option is correctly associated with biotechnology.

### Final Conclusion:
- The odd one out is **Option 3: Solar Energy Converter** because it does not relate to the other concepts, which are all associated with biological or environmental sciences.