**Core Concept**
The patient's presentation suggests a diagnosis of Infectious Mononucleosis (IM), caused by the Epstein-Barr Virus (EBV). This condition is characterized by fever, sore throat, lymphadenopathy, and hepatosplenomegaly, often accompanied by atypical lymphocytosis.

**Why the Correct Answer is Right**
The correct answer is related to a known complication of Infectious Mononucleosis. Splenic rupture is a well-documented risk in patients with IM, particularly during physical exertion or minor trauma. The spleen becomes enlarged and fragile due to the EBV infection, leading to an increased risk of rupture. This is a significant concern in patients with IM, as it can be life-threatening if not promptly recognized and treated.

**Why Each Wrong Option is Incorrect**

* **Option A:** While hemolytic anemia can occur in various conditions, it is not a direct complication of Infectious Mononucleosis. The Coombs' test is positive, indicating an autoimmune hemolytic anemia, but this is not the most likely complication of IM.
* **Option B:** Lymphoma is a rare complication of EBV infection, but it is not the most likely complication in this scenario. While EBV is associated with certain types of lymphoma, such as Burkitt lymphoma, this is not the primary concern in a patient with IM.
* **Option D:** While patients with IM may experience fatigue and general malaise, aplastic anemia is not a known complication of this condition.

**Clinical Pearl / High-Yield Fact**
In patients with Infectious Mononucleosis, the spleen is often enlarged and tender, and patients may experience pain in the left upper quadrant of the abdomen. It is essential to avoid physical exertion or contact sports in these patients to minimize the risk of splenic rupture.

**Correct Answer: C. Splenic rupture.**