Which of the following is a pathogenic form of Entamoeba histolytica?

Options

A. Quadrinucleate cyst
B. Binucleate cyst
C. Minute form
D. Magna form

Answer

To determine which of the following is a pathogenic form of Entamoeba histolytica, we need to analyze the different forms of this protozoan parasite.

### Step-by-Step Solution:

1. **Understand the Forms of Entamoeba histolytica**:
- Entamoeba histolytica exists in two primary forms: the trophozoite and the cyst.
- The trophozoite is the active, dividing form, while the cyst is the dormant stage that can survive outside the host.

2. **Evaluate the Options**:
- **Option 1: Quadrenucleic cyst**: This form is infectious and can cause intestinal amoebiasis when ingested through contaminated food or water. This is a pathogenic form.
- **Option 2: Binucleate cyst**: This form is not infectious and develops under unfavorable conditions for trophozoites. It does not cause disease, making it non-pathogenic.
- **Option 3: Minute cyst**: This is a simple cyst and is also not infectious, thus non-pathogenic.
- **Option 4: Magnaform**: This refers to the trophozoite form, which is not infectious or pathogenic.

3. **Conclusion**:
- After evaluating all options, the **Quadrenucleic cyst** is identified as the pathogenic form of Entamoeba histolytica because it is capable of causing disease upon ingestion.

### Final Answer:
The pathogenic form of Entamoeba histolytica is the **Quadrenucleic cyst**.