Just as Xenopsylla is to Yersinia pestis, so is:

Options

A. Glossina palplis to Wuchereria bancrofti
B. Culex to Plasmodium falciparum
C. Homo sapiens to Taenia solium
D. Phlebotomus to Leishmaina donovani

Answer

To solve the question, we need to identify the relationship between Xenopsylla and Yersinia pestis and then find a similar relationship among the given options.

### Step-by-Step Solution:

1. **Understanding the Relationship**:
- Xenopsylla is a flea that acts as a vector for Yersinia pestis, which is the bacterium that causes plague. This means that Xenopsylla is responsible for transmitting the disease-causing organism to humans.

2. **Analyzing the Options**:
- **Option A**: Leucina palpis to Wuchereria bancrofti
- Wuchereria bancrofti is a parasitic worm that causes lymphatic filariasis, and it is transmitted by mosquitoes, not by Leucina palpis. Hence, this option is incorrect.

- **Option B**: Culex to Plasmodium falciparum
- Plasmodium falciparum is a protozoan that causes malaria, and it is transmitted by Anopheles mosquitoes, not Culex. Therefore, this option is also incorrect.

- **Option C**: Homo sapiens to Taenia solium
- Taenia solium (pork tapeworm) is transmitted to humans through the ingestion of infected pork. There is no vector involved in this transmission. Thus, this option is incorrect.

- **Option D**: Phlebotomus to Leishmania donovani
- Phlebotomus is a sandfly that acts as a vector for Leishmania donovani, which causes leishmaniasis. This is a similar relationship to that of Xenopsylla and Yersinia pestis.

3. **Conclusion**:
- The correct answer is **Option D: Phlebotomus to Leishmania donovani**, as it maintains the same vector-pathogen relationship as Xenopsylla to Yersinia pestis.

### Final Answer:
**Option D: Phlebotomus to Leishmania donovani**