**Core Concept**
Post radical neck dissection shoulder syndrome (PRNDSS) is a condition that arises after a radical neck dissection surgery, where the nerves and muscles controlling shoulder movement are compromised. This leads to a range of clinical manifestations, including pain, weakness, and restricted movement.

**Why the Correct Answer is Right**
The primary cause of PRNDSS is the injury to the spinal accessory nerve (SAN) and the brachial plexus, which are essential for shoulder movement. Injury to these nerves disrupts the normal functioning of the trapezius and levator scapulae muscles, resulting in shoulder drooping, pain, and restricted movement. However, electromyography (EMG) is a diagnostic tool that evaluates the electrical activity of muscles and can detect abnormalities in muscle function. In the case of PRNDSS, EMG would likely show abnormal findings, such as reduced muscle activity or denervation potentials, indicating nerve damage.

**Why Each Wrong Option is Incorrect**
**Option A:** Restricted range of movement is a common symptom of PRNDSS due to the compromised nerve supply to the shoulder muscles.
**Option B:** Pain is another characteristic symptom of PRNDSS, resulting from the injury to the nerves and muscles controlling shoulder movement.
**Option C:** Shoulder drooping is a classic sign of PRNDSS, resulting from the weakness of the trapezius muscle due to SAN injury.

**Clinical Pearl / High-Yield Fact**
It is essential for surgeons to identify and repair the SAN and brachial plexus during radical neck dissection to prevent PRNDSS. Early recognition and treatment of PRNDSS can improve patient outcomes and prevent long-term disability.

**Correct Answer:**
✓ Correct Answer: D. Normal electromyographic finding