**Core Concept**
Pleomorphic adenoma, also known as a benign mixed tumor, is a common type of salivary gland tumor that primarily affects the parotid gland. It is characterized by its diverse histological appearance, consisting of both epithelial and mesenchymal components. The treatment of choice for pleomorphic adenoma is surgical excision, aiming to remove the tumor completely while preserving surrounding tissues and maintaining facial nerve function.

**Why the Correct Answer is Right**
The treatment of choice for pleomorphic adenoma is surgical excision, typically through a superficial parotidectomy or a total parotidectomy, depending on the tumor's size and location. This approach allows for complete removal of the tumor, reducing the risk of recurrence and malignant transformation. The surgical procedure also enables the preservation of the facial nerve, which is critical for maintaining facial function and cosmesis.

**Why Each Wrong Option is Incorrect**
**Option A:** Enucleation, or the removal of the tumor by scooping it out, is not the treatment of choice for pleomorphic adenoma, as it may lead to incomplete removal and an increased risk of recurrence.
**Option B:** Radiation therapy is not a primary treatment for pleomorphic adenoma, as it is typically reserved for malignant tumors or in cases where surgical excision is not feasible.
**Option C:** Fine-needle aspiration cytology (FNAC) is a diagnostic tool used to confirm the presence of a pleomorphic adenoma, but it is not a treatment option.

**Clinical Pearl / High-Yield Fact**
It is essential to note that pleomorphic adenomas have a high propensity for recurrence if not completely excised, emphasizing the importance of thorough surgical removal and histopathological examination to confirm the absence of tumor cells at the margins.

**Correct Answer:** C. Surgical excision.