Anatomy All of the following are found in the posterior triangle of the neck except one. Which one is the exception? A External jugular vein. B Subclavian vein. C Hypoglossal nerve. D Phrenic nerve. 💡 Explanation All of the following are found in the posterior triangle of the neck except one. Which one is the exception? ✓ Correct Answer: C. Hypoglossal nerve.