**Core Concept**
Entamoeba histolytica is a protozoan parasite that causes amoebiasis, a type of intestinal infection. The parasite has a complex life cycle, with two main forms: cysts and trophozoites. The cysts are the infectious form, while the trophozoites are the actively feeding and multiplying form.

**Why the Correct Answer is Right**
The cysts of Entamoeba histolytica typically contain four nuclei, which are visible under a microscope. The four-nucleated cysts are the infectious form of the parasite and are responsible for the transmission of amoebiasis. The trophozoites of Entamoeba histolytica colonize the large intestine and can cause invasive amoebiasis, leading to symptoms such as diarrhea, abdominal pain, and weight loss. The chromatoid bodies, also known as chromatoid bars, are a characteristic feature of the trophozoites of Entamoeba histolytica and are stained by iodine.

**Why Each Wrong Option is Incorrect**
**Option A:** Cyst are 8 nucleated - This is incorrect because the cysts of Entamoeba histolytica typically contain four nuclei, not eight.
**Option B:** Cyst are 4 nucleated - This is correct, so we won't explain why it's wrong.
**Option C:** Trophozoites colonise in the colon - This is correct, as the trophozoites of Entamoeba histolytica colonize the large intestine.
**Option D:** The chromatid bodies are stained by Iodides - This is incorrect because the chromatoid bodies are actually stained by iodine, not iodides.

**Clinical Pearl / High-Yield Fact**
It's essential to note that the cysts of Entamoeba histolytica are the infectious form of the parasite and are responsible for the transmission of amoebiasis. The cysts can be detected in stool samples using microscopy and are typically treated with antiparasitic medications.

**Correct Answer: C. Trophozoites colonise in the colon**