Ecological sanitation is a sustainable system for handling human excreta, using dry composting toilets. Such 'EcoSan' toilets are working in many areas of:

Options

A. Assam and West Bengal
B. Maharashtra and Andhra Pradesh
C. Kerala and Sri Lanka
D. Karanataka and Andhra Pradesh

Answer

### Step-by-Step Solution:

1. **Understanding Ecological Sanitation**:
- Ecological sanitation (EcoSan) refers to a sustainable system designed to handle human excreta. It emphasizes the use of dry composting toilets, which are an environmentally friendly alternative to traditional sanitation methods.

2. **Functionality of EcoSan Toilets**:
- EcoSan toilets operate by composting human waste. This process allows for the recycling of excreta into valuable resources, such as natural fertilizers, which can be used in agriculture.

3. **Benefits of EcoSan Toilets**:
- These toilets provide a practical, hygienic, efficient, and cost-effective solution for managing human waste. They also help reduce the dependency on chemical fertilizers, promoting a more sustainable agricultural practice.

4. **Geographical Implementation**:
- EcoSan toilets have been implemented in various regions, particularly in India and some neighboring countries. The question specifically asks about areas where these toilets are operational.

5. **Identifying Areas**:
- According to the information provided, EcoSan toilets are notably functioning in Kerala, India, and also in Sri Lanka. These regions have adopted this sustainable sanitation system effectively.

6. **Conclusion**:
- Based on the above points, the areas where EcoSan toilets are operational include **Kerala (India)** and **Sri Lanka**.

### Final Answer:
**Kerala and Sri Lanka**

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