## **Core Concept**
The question describes a clinical scenario suggestive of a parasitic intestinal infection, given the symptoms of intermittent abdominal cramps and loose stool, along with the presence of eggs in the stool. The size of the eggs (100 μm) is a critical clue for identifying the causative parasite.

## **Why the Correct Answer is Right**
The correct answer, **D.**, implies that the other options are associated with eggs of approximately 100 μm in size. Common intestinal parasites with eggs around this size include *Trichuris trichiura* (whipworm), with eggs measuring about 90-100 μm. This parasite causes gastrointestinal symptoms like abdominal cramps and diarrhea.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is likely associated with a parasite that has eggs of a size consistent with 100 μm, making it a plausible cause.
- **Option B:** Similarly, this option could be related to another parasite with eggs around 100 μm, making it incorrect as a "not cause."
- **Option C:** This option might also correspond to a parasite with eggs of a similar size, thus not being the correct answer to the question about which is "not the cause."

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that *Trichuris trichiura* infections are treated with anthelmintics like albendazole or mebendazole. The presence of large eggs (around 100 μm) in stool is highly suggestive of *Trichuris trichiura* infection.

## **Correct Answer:** **D.**