This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General surgery, Subject name: Surgery
Posterior triangle lymph nodes are 
Select and explain. 
A. Level 4, B. Level 5, C. Level 6, D. Level 7
B: Level 5
Answer: B: Level 5 
Explanation: ISub mandibulaeIIUpper deep cervicalIIIMid-cervicalIVLower cervicalVPosterior triangleVIPre laryngeal/pre trachealVIIMediastinalRef: Bailey and love pg: 764