Gambusia fish is successfully utilized for

Options

A. Kill causative agent of malaria
B. Destroy the vector agent of malaria
C. Destroy larval stage vector of malaria responsible for transmitting the disease.
D. Make the environment unfavorable for growth of vector agent of malaria

Answer

To solve the question regarding the utilization of Gambusia fish, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks about the successful utilization of Gambusia fish. We need to identify its role in relation to malaria.

2. **Identifying the Causative Agent of Malaria**: The causative agent of malaria is the Plasmodium parasite, which requires a vector for its transmission.

3. **Identifying the Vector of Malaria**: The primary vector for malaria transmission is the female Anopheles mosquito. The mosquito carries the Plasmodium parasite from one host (human) to another.

4. **Role of Gambusia Fish**: Gambusia fish, also known as mosquito fish, are known for their ability to feed on mosquito larvae. By consuming these larvae, Gambusia helps to control the mosquito population.

5. **Analyzing the Options**:
- **Option A**: Kill causative agent of malaria - Incorrect, as Gambusia does not kill the Plasmodium parasite directly.
- **Option B**: Destroy vector agent of malaria - Incorrect, as it does not destroy adult mosquitoes directly.
- **Option C**: Destroy larval stage vector of malaria responsible for transmitting the disease - Correct, as Gambusia feeds on mosquito larvae.
- **Option D**: Make the environment unfavorable for growth of vector agent of malaria - Incorrect, as it specifically targets the larvae rather than altering the environment.

6. **Conclusion**: The most accurate answer is **Option C**: Gambusia fish is successfully utilized to destroy the larval stage vector of malaria responsible for transmitting the disease.

### Final Answer:
C. Destroy larval stage vector of malaria responsible for transmitting the disease.