**Core Concept**
The patient's symptoms, including explosive watery diarrhea with blood, fecal leukocytes, and mucus, suggest an infection caused by a bacterial pathogen that invades the intestinal mucosa, leading to an inflammatory response.

**Why the Correct Answer is Right**
The presence of curved rods in the fecal smear, along with red blood cells and leukocytes, is indicative of a bacterial infection caused by *Campylobacter jejuni*. This bacterium is commonly associated with undercooked poultry, such as chicken, and can cause a self-limiting, but often severe, gastroenteritis. The pathogenesis of *C. jejuni* involves the attachment of the bacteria to the intestinal mucosa, followed by the invasion of the epithelial cells, which leads to an inflammatory response and the production of pro-inflammatory cytokines.

**Why Each Wrong Option is Incorrect**
**Option A:** Salmonella species are also associated with foodborne illnesses, but they typically cause a more systemic infection, including fever, headache, and abdominal cramps, rather than just explosive diarrhea.

**Option B:** Shigella species are known to cause dysentery, characterized by bloody diarrhea, but they are less commonly associated with undercooked poultry and more often linked to contaminated water or food.

**Option C:** Enterohemorrhagic *Escherichia coli* (EHEC) can cause a similar syndrome, but it is more commonly associated with ground beef or unpasteurized apple cider, rather than undercooked chicken.

**Clinical Pearl / High-Yield Fact**
When considering a foodborne illness, remember that the incubation period (the time from ingestion of the pathogen to the onset of symptoms) can provide clues to the etiology: *Campylobacter jejuni* typically has an incubation period of 2-5 days, while *Salmonella* and *Shigella* usually have a shorter incubation period of 6-48 hours.

**Correct Answer:** C. *Campylobacter jejuni*.