**Core Concept**
The question is testing the student's knowledge of viruses that are shed in stool, which is an important aspect of infectious disease medicine. This concept is crucial for understanding the transmission and diagnosis of various gastrointestinal infections.

**Why the Correct Answer is Right**
The correct answer is a virus that primarily infects the gastrointestinal tract and is commonly transmitted through the fecal-oral route. This virus replicates in the epithelial cells of the small intestine, leading to inflammation and diarrhea. The virus is highly contagious and can be shed in high quantities in stool, making it a significant public health concern.

**Why Each Wrong Option is Incorrect**

* **Option A:** This virus is primarily shed in respiratory secretions and is not typically associated with gastrointestinal symptoms.
* **Option B:** This virus is primarily shed in saliva and is not typically associated with gastrointestinal symptoms.
* **Option C:** This virus is primarily shed in urine and is not typically associated with gastrointestinal symptoms.

**Clinical Pearl / High-Yield Fact**
One important point to remember is that viruses that are shed in stool can be highly contagious and can be transmitted through contaminated food and water. This highlights the importance of proper hand hygiene and sanitation practices in preventing the spread of gastrointestinal infections.

**Correct Answer: C. Rotavirus**