Okay, let's tackle this question about the mature cyst of Entamoeba histolytica. The question is asking how many nuclei are present in a mature cyst. I remember that E. histolytica has a life cycle that includes both trophozoites and cysts. The cysts are the infective form, right?

First, I need to recall the structure of the cyst. I think when the organism is in the cyst form, it's dormant and more resistant to environmental conditions. The number of nuclei is a key diagnostic feature. I remember that in the early stages, the cyst might have fewer nuclei. Let me think: the trophozoites are usually uninucleate, but when they form a cyst, they undergo division without cell division, leading to more nuclei.

Wait, the life cycle stages: the trophozoite can encyst, forming a four-nucleated cyst, which is the mature form. The immature cysts might have two nuclei. So the mature cyst has four nuclei. That's a key point because other similar organisms might have different numbers. For example, Entamoeba coli has more nuclei, like 8-16, but that's not the case here.

Now, looking at the options. The correct answer should be 4. The other options might be 1, 2, or 8. Let's check each. Option A (if it's 1) would be incorrect because the mature cyst isn't uninucleate. Option B (2) would be the immature stage. Option C (4) is correct. Option D (8) is for other organisms or maybe for non-mature stages.

Clinical pearl: The number of nuclei in the cyst is crucial for differentiation. E. histolytica's mature cyst has four nuclei, which is distinct from other Entamoeba species. This is a high-yield point for parasitology exams. Also, the presence of chromatoidal bars in the cyst is another characteristic feature.

**Core Concept**
The mature cyst of *Entamoeba histolytica* is a diagnostic stage in its life cycle, characterized by a specific number of nuclei. This feature distinguishes it from other *Entamoeba* species and is critical for accurate identification in stool samples.

**Why the Correct Answer is Right**
The mature *E. histolytica* cyst contains **four nuclei**. During encystation, a trophozoite undergoes two successive divisions without cytokinesis, resulting in a quadrinucleated cyst. The nuclei are small, round, and centrally located, with a distinct karyosome and peripheral chromatin. This stage is the infective form transmitted via the fecal-oral route.

**Why Each Wrong Option is Incorrect**
**Option A (1 nucleus):** Uninucleate cysts are not a stage in *E. histolytica*; this applies to trophozoites.
**Option B (2 nuclei):** A binucleate cyst represents an immature stage, not the mature form.
**Option D (8 nuclei):** Octanucleate cysts are characteristic of *Entamoeba coli*, not *E. histolytica*.

**Clinical Pearl / High-Yield Fact**
Remember: *E. histolytica* mature cysts = **4 nuclei**. Differentiate from *E. coli* (8–

✓ Correct Answer: C. 4