**Core Concept**
Idiopathic Thrombocytopenic Purpura (ITP) is an autoimmune disease characterized by isolated thrombocytopenia, which can present with petechiae, purpura, and mucocutaneous bleeding. Aspirin, an antiplatelet agent, can exacerbate bleeding in ITP patients.

**Why the Correct Answer is Right**
In this case, the patient's history of viral infection followed by treatment with aspirin is suggestive of ITP. The virus may trigger an autoimmune response leading to platelet destruction. Aspirin further increases the risk of bleeding by inhibiting platelet aggregation. ITP is diagnosed by ruling out other causes of thrombocytopenia and demonstrating isolated thrombocytopenia on laboratory tests.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it doesn't account for the patient's history of aspirin use and viral infection, which are key factors in the development of ITP.
**Option B:** This option is incorrect because thrombocytopenia is not the primary concern in this case; rather, it's the patient's bleeding symptoms and history of aspirin use.
**Option C:** This option is incorrect because it doesn't take into account the patient's recent history of viral infection and aspirin use, which are critical in diagnosing ITP.

**Clinical Pearl / High-Yield Fact**
Remember the "6 Ps" of ITP diagnosis: Petechiae, Purpura, Platelet count below 100,000/µL, Positive Coombs test, and Pregnancy (which can trigger ITP).

**Correct Answer: A. ITP**