**Core Concept**
A large antrochoanal polyp is a type of nasal polyp that originates from the maxillary sinus and extends into the nasopharynx, causing nasal obstruction and other symptoms. The treatment of choice for this condition is surgical removal, as medical management is often ineffective in reducing the size of the polyp.

**Why the Correct Answer is Right**
The current treatment of choice for a large antrochoanal polyp is endoscopic sinus surgery (ESS). ESS is a minimally invasive procedure that allows for the removal of the polyp and the opening of the maxillary sinus ostium to promote drainage and prevent recurrence. This procedure is typically performed under general anesthesia and is preferred over traditional open surgery due to its reduced morbidity and faster recovery time.

**Why Each Wrong Option is Incorrect**
**Option A:** Antibiotics are not the primary treatment for antrochoanal polyps, as they are often unresponsive to medical management. While antibiotics may be used to treat any underlying infection, they do not address the underlying cause of the polyp.
**Option B:** Nasal decongestants and corticosteroids may provide temporary relief from symptoms, but they do not address the underlying issue of the polyp itself. These medications may be used as adjunctive therapy, but they are not sufficient as a standalone treatment.
**Option C:** Radiofrequency ablation is a treatment option for some nasal polyps, but it is not the preferred treatment for large antrochoanal polyps. This procedure may be used for smaller polyps or as an adjunct to ESS.

**Clinical Pearl / High-Yield Fact**
It is essential to note that antrochoanal polyps are often associated with a higher risk of recurrence, especially if the underlying cause is not addressed. Therefore, a thorough evaluation of the maxillary sinus and nasal cavity is necessary to identify any underlying anatomical abnormalities or conditions that may contribute to the formation of the polyp.

**Correct Answer: C. Endoscopic sinus surgery (ESS)**