The vector for causing sleeping sickness in man is

Options

A. House fly
B. Mosquito
C. Tse-tse fly
D. Sand fly

Answer

**Step-by-Step Solution:**

1. **Understand the Question**: The question asks for the vector that causes sleeping sickness in humans. A vector is an organism that transmits a disease or parasite from one host to another.

2. **Evaluate the Options**: The question provides multiple options. We need to analyze each option to determine which one is the correct vector for sleeping sickness.

3. **Analyze Option 1 - Housefly**: The first option is the housefly. Houseflies are known to transmit diseases like typhoid fever and cholera, but they are not associated with sleeping sickness. Therefore, this option is incorrect.

4. **Analyze Option 2 - Mosquito**: The second option is the mosquito. Mosquitoes are vectors for diseases such as malaria, dengue, and Zika virus. However, they do not transmit sleeping sickness. Thus, this option is also incorrect.

5. **Analyze Option 3 - Fly**: The third option is simply stated as "Fly." This is a broader category but is often associated with the tsetse fly, which is the specific vector responsible for transmitting the Trypanosoma parasite that causes sleeping sickness in humans. Therefore, this option is likely correct.

6. **Analyze Option 4 - Sand Fly**: The fourth option is the sand fly. Sand flies are known to transmit leishmaniasis but are not responsible for sleeping sickness. Hence, this option is incorrect.

7. **Conclusion**: After evaluating all the options, the correct answer is option 3, which refers to the fly (specifically the tsetse fly) as the vector for sleeping sickness in humans.

**Final Answer**: The vector for causing sleeping sickness in man is the tsetse fly (option 3).

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