Which one is correct?

Options

A. Salmonella typhii and Haemophilus influenzae cause pneumonia
B. Widal test is done for malaria
C. Entamoeba histolytica causes amoebiasis
D. Wuchereria causes enterobiasis.

Explanation

To solve the question "Which one is correct?" regarding the statements about various pathogens and diseases, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Option 1: Salmonella typhi and Haemophilus influenzae cause pneumonia.**
- **Analysis:**
- Salmonella typhi is known to cause typhoid fever, not pneumonia.
- Haemophilus influenzae can cause pneumonia, but the statement incorrectly includes Salmonella typhi.
- **Conclusion:** This statement is **incorrect**.

2. **Option 2: Vidal test is done for malaria.**
- **Analysis:**
- The Vidal test is specifically used to detect typhoid fever caused by Salmonella typhi.
- It is not used for diagnosing malaria.
- **Conclusion:** This statement is **incorrect**.

3. **Option 3: Entamoeba histolytica causes amoebiasis.**
- **Analysis:**
- Entamoeba histolytica is indeed the causative agent of amoebiasis, also known as amoebic dysentery.
- **Conclusion:** This statement is **correct**.

4. **Option 4: Butcheria causes enterobiosis.**
- **Analysis:**
- Enterobiosis is caused by pinworms, specifically Enterobius vermicularis.
- Butcheria is associated with diseases like filariasis or elephantiasis, not enterobiosis.
- **Conclusion:** This statement is **incorrect**.

### Final Answer:
The correct statement is: **Entamoeba histolytica causes amoebiasis.**