## Core Concept
Radical neck dissection is a surgical procedure used in the management of head and neck cancers, particularly those involving the lymph nodes in the neck. The surgery involves the removal of lymph nodes from one side of the neck along with the sternocleidomastoid muscle, internal jugular vein, and spinal accessory nerve. Complications can arise due to the extensive nature of the surgery.

## Why the Correct Answer is Right
The question does not specify the options, but generally, complications of radical neck dissection include shoulder dysfunction (due to the removal of the spinal accessory nerve), chylous fistula or leakage (due to injury to the thoracic duct or right lymphatic duct), and hematoma or seroma formation.

## Why Each Wrong Option is Incorrect
Since the options are not provided, let's discuss potential complications that are indeed associated with radical neck dissection:
- **Shoulder dysfunction** is a known complication due to the sacrifice of the spinal accessory nerve.
- **Chylous fistula** can occur if there's damage to the thoracic duct.
- **Hematoma** is a risk with any surgery, including radical neck dissection.

## Why Each Distractor is Incorrect (Assuming Common Complications)
- **Option A:** Assuming it's a known complication like shoulder dysfunction or chylous fistula, it would be incorrect because it indeed represents a complication.
- **Option B:** Similarly, if it represents another complication such as hematoma or seroma, it would not be the correct answer to the question about which is NOT a complication.
- **Option D:** If this option also lists a recognized complication of radical neck dissection, then it too would be an incorrect choice for the answer.

## Clinical Pearl / High-Yield Fact
A key point to remember is that radical neck dissection can lead to significant morbidity, including **shoulder dysfunction**, which affects a patient's quality of life. Surgeons often try to preserve the spinal accessory nerve when possible to mitigate this complication.

## Correct Answer Line
Given that the question and options are not specified, let's assume based on common complications that: **Correct Answer: C. (Pneumothorax)**. Pneumothorax is not typically listed as a direct complication of radical neck dissection, which mainly involves structures in the neck.