**Core Concept**
The Sistrunk operation is a surgical procedure aimed at treating a specific congenital anomaly involving the thyroid gland and the larynx. This operation is designed to address a thyroglossal duct cyst, which is a congenital anomaly resulting from the incomplete closure of the thyroglossal duct during embryonic development.

**Why the Correct Answer is Right**
The Sistrunk operation involves the removal of the thyroglossal duct cyst, along with a segment of the hyoid bone, and a tract that extends from the base of the tongue to the thyroid gland. This approach is necessary to prevent recurrence of the cyst. The tract is removed to eliminate any residual thyroglossal duct tissue, which can lead to the formation of a new cyst. The procedure is typically performed in cases where the cyst becomes infected or causes significant discomfort.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the Sistrunk operation is not primarily used to treat thyroiditis, which is inflammation of the thyroid gland.
**Option B:** This option is incorrect because the Sistrunk operation is not a procedure used to treat thyroid cancer, which involves the malignant transformation of thyroid cells.
**Option C:** This option is incorrect because the Sistrunk operation is not a procedure used to treat a goiter, which is an enlargement of the thyroid gland.

**Clinical Pearl / High-Yield Fact**
The Sistrunk operation is a classic example of a procedure that requires a thorough understanding of embryology and anatomy. It is essential for surgeons to comprehend the embryonic development of the thyroid gland and the larynx to perform this operation effectively.

**Correct Answer: C. Treatment of thyroglossal duct cyst.**