**Core Concept**
Antrochoanal polyps, hemangiomas, angiofibromas, and rhinoliths are distinct nasal masses with different characteristics and clinical presentations. Angiofibromas are particularly notable for their high prevalence in adolescent males, typically presenting with recurrent, severe epistaxis.

**Why the Correct Answer is Right**
Angiofibromas are benign, highly vascular tumors that arise from the nasal mucosa, particularly in the posterior nasal cavity. They are most commonly seen in adolescent males, with a peak incidence around 14-15 years of age. The high vascularity of these tumors leads to recurrent, severe epistaxis, which is a hallmark symptom. The unilateral nasal mass and recurrent epistaxis in a 10-year-old boy are highly suggestive of an angiofibroma.

**Why Each Wrong Option is Incorrect**

* **Option A:** Antrochoanal polyps are benign, slow-growing lesions that arise from the maxillary sinus and extend into the nasal cavity. They are typically unilateral but do not present with recurrent epistaxis.
* **Option B:** Hemangiomas are benign vascular tumors that can occur in the nasal cavity, but they are more commonly seen in infants and children. They do not typically present with recurrent epistaxis or a unilateral nasal mass in this age group.
* **Option D:** Rhinoliths are calcified masses that form around foreign bodies in the nasal cavity. They can present with nasal obstruction, but recurrent epistaxis is not a characteristic symptom.

**Clinical Pearl / High-Yield Fact**
In adolescent males with recurrent epistaxis and a unilateral nasal mass, angiofibroma should be a top differential diagnosis. These tumors can be challenging to diagnose and manage due to their high vascularity and tendency to bleed.

**✓ Correct Answer: C. Angiofibroma**