**Core Concept**
Acute hemorrhagic conjunctivitis is a highly contagious and severe form of conjunctivitis characterized by sudden onset of hemorrhage and edema of the conjunctiva. It is often caused by specific viral or bacterial pathogens that trigger a intense inflammatory response.

**Why the Correct Answer is Right**
The correct answer is Pneumococcus, specifically *Streptococcus pneumoniae*, which is a gram-positive bacterium known to cause a range of infections, including conjunctivitis. Pneumococcal conjunctivitis is often associated with the production of a toxin that induces inflammation and hemorrhage of the conjunctiva. This toxin triggers the release of pro-inflammatory cytokines and mediators, leading to the characteristic symptoms of acute hemorrhagic conjunctivitis.

**Why Each Wrong Option is Incorrect**
* **Option A:** Staphylococcus aureus is a gram-positive bacterium that can cause conjunctivitis, but it is typically associated with a more chronic and less severe form of the disease, often accompanied by a purulent discharge.
* **Option B:** Streptococcus hemolyticus is a group of streptococci that can cause a range of infections, but it is not typically associated with acute hemorrhagic conjunctivitis.
* **Option D:** Pseudomonas is a gram-negative bacterium that can cause opportunistic infections, including conjunctivitis, particularly in immunocompromised individuals, but it is not the primary cause of acute hemorrhagic conjunctivitis.

**Clinical Pearl / High-Yield Fact**
It is essential to note that Pneumococcal conjunctivitis can be prevented with the use of pneumococcal vaccines, which are particularly important in high-risk populations, such as young children and older adults.

✓ Correct Answer: C. Pneumococcus