**Core Concept**
Multiple Endocrine Neoplasia Type 2B (MEN-2B) is a rare genetic disorder characterized by the development of medullary thyroid carcinoma, pheochromocytoma, and other endocrine tumors. It is caused by a mutation in the RET proto-oncogene, leading to the activation of the MAPK signaling pathway and subsequent tumor formation.

**Why the Correct Answer is Right**
The management of MEN-2B involves early diagnosis and prophylactic thyroidectomy to prevent the development of medullary thyroid carcinoma. This is because the RET mutation is present from birth and the risk of developing medullary thyroid carcinoma is high. Prophylactic thyroidectomy can significantly reduce the risk of cancer and improve survival. The surgery is typically performed before the age of 5, and it is essential to remove the thyroid gland to prevent the spread of cancer.

**Why Each Wrong Option is Incorrect**
**Option A:** Waiting for symptoms to develop is not a suitable approach, as the symptoms of MEN-2B may not appear until the cancer has spread.
**Option B:** Screening for pheochromocytoma is essential, but it is not the primary line of management for MEN-2B.
**Option C:** Genetic testing can confirm the diagnosis, but it is not a substitute for prophylactic thyroidectomy.

**Clinical Pearl / High-Yield Fact**
MEN-2B is a rare but highly malignant disorder that requires early diagnosis and aggressive management to prevent cancer development. Prophylactic thyroidectomy is the cornerstone of management, and it should be performed before the age of 5 to improve survival.

**Correct Answer:** C. Prophylactic thyroidectomy.